/*

Copyright (c) 2003, Arvid Norberg
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

*/

#include "libtorrent/pch.hpp"

#include <ctime>
#include <algorithm>
#include <set>
#include <cctype>
#include <numeric>

#ifdef TORRENT_DEBUG
#include <iostream>
#endif

#ifdef _MSC_VER
#pragma warning(push, 1)
#endif

#include <boost/bind.hpp>

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#include "libtorrent/config.hpp"
#include "libtorrent/torrent_handle.hpp"
#include "libtorrent/session.hpp"
#include "libtorrent/torrent_info.hpp"
#include "libtorrent/tracker_manager.hpp"
#include "libtorrent/parse_url.hpp"
#include "libtorrent/bencode.hpp"
#include "libtorrent/hasher.hpp"
#include "libtorrent/entry.hpp"
#include "libtorrent/peer.hpp"
#include "libtorrent/peer_connection.hpp"
#include "libtorrent/bt_peer_connection.hpp"
#include "libtorrent/web_peer_connection.hpp"
#include "libtorrent/http_seed_connection.hpp"
#include "libtorrent/peer_id.hpp"
#include "libtorrent/alert.hpp"
#include "libtorrent/identify_client.hpp"
#include "libtorrent/alert_types.hpp"
#include "libtorrent/extensions.hpp"
#include "libtorrent/aux_/session_impl.hpp"
#include "libtorrent/instantiate_connection.hpp"
#include "libtorrent/assert.hpp"
#include "libtorrent/broadcast_socket.hpp"
#include "libtorrent/kademlia/dht_tracker.hpp"
#include "libtorrent/peer_info.hpp"
#include "libtorrent/enum_net.hpp"
#include "libtorrent/http_connection.hpp"
#include "libtorrent/gzip.hpp" // for inflate_gzip
#include "libtorrent/random.hpp"

#ifdef TORRENT_USE_OPENSSL
#include "libtorrent/ssl_stream.hpp"
#include <boost/asio/ssl/context.hpp>
//#include <boost/asio/ssl/verify_context.hpp>
#endif

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
#include "libtorrent/struct_debug.hpp"
#endif

#if TORRENT_USE_IOSTREAM
#include <iostream>
#endif

using namespace libtorrent;
using boost::tuples::tuple;
using boost::tuples::get;
using boost::tuples::make_tuple;
using libtorrent::aux::session_impl;

namespace
{
    size_type collect_free_download(
        torrent::peer_iterator start
        , torrent::peer_iterator end)
    {
        size_type accumulator = 0;
        for (torrent::peer_iterator i = start; i != end; ++i)
        {
            // if the peer is interested in us, it means it may
            // want to trade it's surplus uploads for downloads itself
            // (and we should not consider it free). If the share diff is
            // negative, there's no free download to get from this peer.
            size_type diff = (*i)->share_diff();
            TORRENT_ASSERT(diff < (std::numeric_limits<size_type>::max)());
            if ((*i)->is_peer_interested() || diff <= 0)
                continue;

            TORRENT_ASSERT(diff > 0);
            (*i)->add_free_upload(-diff);
            accumulator += diff;
            TORRENT_ASSERT(accumulator > 0);
        }
        TORRENT_ASSERT(accumulator >= 0);
        return accumulator;
    }

    // returns the amount of free upload left after
    // it has been distributed to the peers
    boost::uint32_t distribute_free_upload(
        torrent::peer_iterator start
        , torrent::peer_iterator end
        , size_type free_upload)
    {
        TORRENT_ASSERT(free_upload >= 0);
        if (free_upload <= 0) return 0;
        int num_peers = 0;
        size_type total_diff = 0;
        for (torrent::peer_iterator i = start; i != end; ++i)
        {
            size_type d = (*i)->share_diff();
            TORRENT_ASSERT(d < (std::numeric_limits<size_type>::max)());
            total_diff += d;
            if (!(*i)->is_peer_interested() || (*i)->share_diff() >= 0) continue;
            ++num_peers;
        }

        if (num_peers == 0) return boost::uint32_t(free_upload);
        size_type upload_share;
        if (total_diff >= 0)
        {
            upload_share = (std::min)(free_upload, total_diff) / num_peers;
        }
        else
        {
            upload_share = (free_upload + total_diff) / num_peers;
        }
        if (upload_share < 0) return boost::uint32_t(free_upload);

        for (torrent::peer_iterator i = start; i != end; ++i)
        {
            peer_connection* p = *i;
            if (!p->is_peer_interested() || p->share_diff() >= 0) continue;
            p->add_free_upload(upload_share);
            free_upload -= upload_share;
        }
        return (std::min)(free_upload, size_type(UINT_MAX));
    }

    struct find_peer_by_ip
    {
        find_peer_by_ip(tcp::endpoint const& a, const torrent* t)
            : ip(a)
            , tor(t)
        { TORRENT_ASSERT(t != 0); }

        bool operator()(session_impl::connection_map::value_type const& c) const
        {
            tcp::endpoint const& sender = c->remote();
            if (sender.address() != ip.address()) return false;
            if (tor != c->associated_torrent().lock().get()) return false;
            return true;
        }

        tcp::endpoint const& ip;
        torrent const* tor;
    };

    struct peer_by_id
    {
        peer_by_id(const peer_id& i): pid(i) {}

        bool operator()(session_impl::connection_map::value_type const& p) const
        {
            if (p->pid() != pid) return false;
            // have a special case for all zeros. We can have any number
            // of peers with that pid, since it's used to indicate no pid.
            if (pid.is_all_zeros()) return false;
            return true;
        }

        peer_id const& pid;
    };
}

namespace libtorrent
{

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING

    void torrent::print_size(logger& l)
    {
        char tmp[300];
        int temp = 0;
        int prev_size = 0;
        PRINT_SIZEOF(torrent)

        PRINT_OFFSETOF(torrent, m_tracker_address)
        PRINT_OFFSETOF(torrent, m_manager)
        PRINT_OFFSETOF(torrent, m_policy)
        PRINT_OFFSETOF(torrent, m_total_uploaded)
        PRINT_OFFSETOF(torrent, m_total_downloaded)
        PRINT_OFFSETOF(torrent, m_started)
        PRINT_OFFSETOF(torrent, m_torrent_file)
        PRINT_OFFSETOF(torrent, m_owning_storage)
        PRINT_OFFSETOF(torrent, m_storage)
        PRINT_OFFSETOF(torrent, m_connections)
        PRINT_OFFSETOF(torrent, m_web_seeds)
#ifndef TORRENT_DISABLE_EXTENSIONS
        PRINT_OFFSETOF(torrent, m_extensions)
#endif
        PRINT_OFFSETOF(torrent, m_tracker_timer)
        PRINT_OFFSETOF(torrent, m_stat)
// some compilers don't like using offsetof on references it seems
#ifndef _MSC_VER
        PRINT_OFFSETOF(torrent, m_ses)
#endif
        PRINT_OFFSETOF(torrent, m_file_priority)
        PRINT_OFFSETOF(torrent, m_file_progress)
        PRINT_OFFSETOF(torrent, m_picker)
        PRINT_OFFSETOF(torrent, m_trackers)
        PRINT_OFFSETOF(torrent, m_time_critical_pieces)
        PRINT_OFFSETOF(torrent, m_username)
        PRINT_OFFSETOF(torrent, m_password)
        PRINT_OFFSETOF(torrent, m_net_interfaces)
        PRINT_OFFSETOF(torrent, m_save_path)
        PRINT_OFFSETOF(torrent, m_url)
        PRINT_OFFSETOF(torrent, m_uuid)
        PRINT_OFFSETOF(torrent, m_source_feed_url)
        PRINT_OFFSETOF(torrent, m_torrent_file_buf)
        PRINT_OFFSETOF(torrent, m_verified)
        PRINT_OFFSETOF(torrent, m_error)
        PRINT_OFFSETOF(torrent, m_error_file)
        PRINT_OFFSETOF(torrent, m_resume_data)
        PRINT_OFFSETOF(torrent, m_resume_entry)
        PRINT_OFFSETOF(torrent, m_name)
        PRINT_OFFSETOF(torrent, m_storage_constructor)
        PRINT_OFFSETOF(torrent, m_added_time)
        PRINT_OFFSETOF(torrent, m_completed_time)
        PRINT_OFFSETOF(torrent, m_last_seen_complete)
        PRINT_OFFSETOF(torrent, m_last_saved_resume)
#ifndef TORRENT_DISABLE_ENCRYPTION
        PRINT_OFFSETOF(torrent, m_obfuscated_hash)
#endif
        PRINT_OFFSETOF(torrent, m_ratio)
        PRINT_OFFSETOF(torrent, m_available_free_upload)
        PRINT_OFFSETOF(torrent, m_average_piece_time)
        PRINT_OFFSETOF(torrent, m_piece_time_deviation)
        PRINT_OFFSETOF(torrent, m_total_failed_bytes)
        PRINT_OFFSETOF(torrent, m_total_redundant_bytes)
//		PRINT_OFFSETOF(torrent, m_upload_mode_time:24)
//		PRINT_OFFSETOF(torrent, m_state:3)
//		PRINT_OFFSETOF(torrent, m_storage_mode:2)
//		PRINT_OFFSETOF(torrent, m_announcing:1)
//		PRINT_OFFSETOF(torrent, m_waiting_tracker:1)
//		PRINT_OFFSETOF(torrent, m_seed_mode:1)
//		PRINT_OFFSETOF(torrent, m_active_time:24)
        PRINT_OFFSETOF(torrent, m_last_working_tracker)
//		PRINT_OFFSETOF(torrent, m_finished_time:24)
//		PRINT_OFFSETOF(torrent, m_sequential_download:1)
//		PRINT_OFFSETOF(torrent, m_got_tracker_response:1)
//		PRINT_OFFSETOF(torrent, m_connections_initialized:1)
//		PRINT_OFFSETOF(torrent, m_super_seeding:1)
//		PRINT_OFFSETOF(torrent, m_override_resume_data:1)
//		PRINT_OFFSETOF(torrent, m_resolving_country:1)
//		PRINT_OFFSETOF(torrent, m_resolve_countries:1)
//		PRINT_OFFSETOF(torrent, m_need_save_resume_data:1)
//		PRINT_OFFSETOF(torrent, m_seeding_time:24)
        PRINT_OFFSETOF(torrent, m_time_scaler)
//		PRINT_OFFSETOF(torrent, m_max_uploads:24)
        PRINT_OFFSETOF(torrent, m_deficit_counter)
//		PRINT_OFFSETOF(torrent, m_num_uploads:24)
//		PRINT_OFFSETOF(torrent, m_block_size_shift:5)
//		PRINT_OFFSETOF(torrent, m_has_incoming:1)
//		PRINT_OFFSETOF(torrent, m_files_checked:1)
//		PRINT_OFFSETOF(torrent, m_queued_for_checking:1)
//		PRINT_OFFSETOF(torrent, m_max_connections:24)
//		PRINT_OFFSETOF(torrent, m_padding:24)
        PRINT_OFFSETOF(torrent, m_sequence_number)
//		PRINT_OFFSETOF(torrent, m_complete:24)
        PRINT_OFFSETOF(torrent, m_priority)
//		PRINT_OFFSETOF(torrent, m_incomplete:24)
//		PRINT_OFFSETOF(torrent, m_progress_ppm:20)
//		PRINT_OFFSETOF(torrent, m_abort:1)
//		PRINT_OFFSETOF(torrent, m_announce_to_dht:1)
//		PRINT_OFFSETOF(torrent, m_announce_to_trackers:1)
//		PRINT_OFFSETOF(torrent, m_announce_to_lsd:1)
//		PRINT_OFFSETOF(torrent, m_allow_peers:1)
//		PRINT_OFFSETOF(torrent, m_upload_mode:1)
//		PRINT_OFFSETOF(torrent, m_auto_managed:1)
        PRINT_OFFSETOF(torrent, m_num_verified)
        PRINT_OFFSETOF(torrent, m_last_scrape)
    }
#undef PRINT_SIZEOF
#undef PRINT_OFFSETOF

#endif

    int root2(int x)
    {
        int ret = 0;
        x >>= 1;
        while (x > 0)
        {
            // if this assert triggers, the block size
            // is not an even 2 exponent!
            TORRENT_ASSERT(x == 1 || (x & 1) == 0);
            ++ret;
            x >>= 1;
        }
        return ret;
    }

#ifndef TORRENT_DISABLE_EXTENSIONS
    // defined in ut_pex.cpp
    bool was_introduced_by(peer_plugin const*, tcp::endpoint const&);
#endif

    torrent::torrent(
        session_impl& ses
        , tcp::endpoint const& net_interface
        , int block_size
        , int seq
        , add_torrent_params const& p
        , sha1_hash const& info_hash)
        : m_policy(this)
        , m_total_uploaded(0)
        , m_total_downloaded(0)
        , m_started(time_now())
        , m_storage(0)
        , m_tracker_timer(ses.m_io_service)
        , m_ses(ses)
        , m_trackerid(p.trackerid)
        , m_save_path(complete(p.save_path))
        , m_url(p.url)
        , m_uuid(p.uuid)
        , m_source_feed_url(p.source_feed_url)
        , m_storage_constructor(p.storage)
        , m_added_time(time(0))
        , m_completed_time(0)
        , m_last_seen_complete(0)
        , m_last_saved_resume(time(0))
        , m_ratio(0.f)
        , m_available_free_upload(0)
        , m_average_piece_time(0)
        , m_piece_time_deviation(0)
        , m_total_failed_bytes(0)
        , m_total_redundant_bytes(0)
        , m_upload_mode_time(0)
        , m_state(torrent_status::checking_resume_data)
        , m_storage_mode(p.storage_mode)
        , m_announcing(false)
        , m_waiting_tracker(false)
        , m_seed_mode(false)
        , m_active_time(0)
        , m_last_working_tracker(-1)
        , m_finished_time(0)
        , m_sequential_download(false)
        , m_got_tracker_response(false)
        , m_connections_initialized(false)
        , m_super_seeding(false)
        , m_override_resume_data(p.override_resume_data)
#ifndef TORRENT_DISABLE_RESOLVE_COUNTRIES
        , m_resolving_country(false)
        , m_resolve_countries(false)
#endif
        , m_need_save_resume_data(true)
        , m_seeding_time(0)
        , m_time_scaler(0)
        , m_max_uploads(~0)
        , m_deficit_counter(0)
        , m_num_uploads(0)
        , m_block_size_shift(root2(block_size))
        , m_has_incoming(false)
        , m_files_checked(false)
        , m_queued_for_checking(false)
        , m_max_connections(~0)
        , m_padding(0)
        , m_sequence_number(seq)
        , m_complete(0xffffff)
        , m_priority(0)
        , m_incomplete(0xffffff)
        , m_progress_ppm(0)
        , m_abort(false)
        , m_announce_to_dht(!p.paused)
        , m_announce_to_trackers(!p.paused)
        , m_announce_to_lsd(!p.paused)
        , m_allow_peers(!p.paused)
        , m_upload_mode(p.upload_mode)
        , m_auto_managed(p.auto_managed)
        , m_share_mode(p.share_mode)
        , m_num_verified(0)
        , m_last_scrape(0)
        , m_last_download(0)
        , m_last_upload(0)
        , m_downloaders(0xffffff)
        , m_interface_index(0)
        , m_save_resume_flags(0)
        , m_graceful_pause_mode(false)
        , m_need_connect_boost(true)
        , m_lsd_seq(0)
        , m_magnet_link(false)
        , m_apply_ip_filter(p.apply_ip_filter)
        , m_merge_resume_trackers(p.merge_resume_trackers)
        , m_in_encrypted_list(false)
    {
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        m_resume_data_loaded = false;
#endif
        if (!m_apply_ip_filter) ++m_ses.m_non_filtered_torrents;

        if (!p.ti || !p.ti->is_valid())
        {
            // we don't have metadata for this torrent. We'll download
            // it either through the URL passed in, or through a metadata
            // extension. Make sure that when we save resume data for this
            // torrent, we also save the metadata
            m_magnet_link = true;

            // did the user provide resume data?
            // maybe the metadata is in there
            if (p.resume_data)
            {
                int pos;
                error_code ec;
                lazy_entry tmp;
                lazy_entry const* info = 0;
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                (*m_ses.m_logger) << time_now_string() << " adding magnet link with resume data\n";
#endif
                if (lazy_bdecode(&(*p.resume_data)[0], &(*p.resume_data)[0]
                    + p.resume_data->size(), tmp, ec, &pos) == 0
                    && tmp.type() == lazy_entry::dict_t
                    && (info = tmp.dict_find_dict("info")))
                {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                    (*m_ses.m_logger) << time_now_string() << " found metadata in resume data\n";
#endif
                    // verify the info-hash of the metadata stored in the resume file matches
                    // the torrent we're loading

                    std::pair<char const*, int> buf = info->data_section();
                    sha1_hash resume_ih = hasher(buf.first, buf.second).final();

                    // if url is set, the info_hash is not actually the info-hash of the
                    // torrent, but the hash of the URL, until we have the full torrent
                    if (resume_ih == info_hash || !p.url.empty())
                    {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                        (*m_ses.m_logger) << time_now_string() << " info-hash matched\n";
#endif
                        m_torrent_file = (p.ti ? p.ti : new torrent_info(resume_ih));

                        if (!m_torrent_file->parse_info_section(*info, ec, 0))
                        {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                            (*m_ses.m_logger) << time_now_string() << " failed to load metadata from resume file: "
                                << ec.message() << "\n";
#endif
                        }
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                        else
                        {
                            (*m_ses.m_logger) << time_now_string() << " successfully loaded metadata from resume file\n";
                        }
#endif
                    }
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                    else
                    {
                        (*m_ses.m_logger) << time_now_string() << " metadata info-hash failed\n";
                    }
#endif
                }
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                else
                {
                    (*m_ses.m_logger) << time_now_string() << " no metadata found\n";
                }
#endif
            }
        }

        if (!m_torrent_file)
            m_torrent_file = (p.ti ? p.ti : new torrent_info(info_hash));

        m_trackers = m_torrent_file->trackers();
        if (m_torrent_file->is_valid())
        {
            m_seed_mode = p.seed_mode;
            m_connections_initialized = true;
            m_block_size_shift = root2((std::min)(block_size, m_torrent_file->piece_length()));
        }
        else
        {
            if (p.name) m_name.reset(new std::string(p.name));
        }

        if (!m_url.empty() && m_uuid.empty()) m_uuid = m_url;

        TORRENT_ASSERT(m_ses.is_network_thread());
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
        (*m_ses.m_logger) << time_now_string() << " creating torrent: "
            << torrent_file().name() << "\n";
#endif
        m_net_interfaces.push_back(tcp::endpoint(net_interface.address(), 0));

        if (p.file_priorities)
            m_file_priority = *p.file_priorities;

        if (m_seed_mode)
            m_verified.resize(m_torrent_file->num_pieces(), false);

        if (p.resume_data) m_resume_data.swap(*p.resume_data);

#ifndef TORRENT_DISABLE_ENCRYPTION
        hasher h;
        h.update("req2", 4);
        h.update((char*)&m_torrent_file->info_hash()[0], 20);
        m_obfuscated_hash = h.final();
#endif

#ifdef TORRENT_DEBUG
        m_files_checked = false;
#endif
        INVARIANT_CHECK;

        if (!m_name && !m_url.empty()) m_name.reset(new std::string(m_url));

        if (p.tracker_url && std::strlen(p.tracker_url) > 0)
        {
            m_trackers.push_back(announce_entry(p.tracker_url));
            m_trackers.back().fail_limit = 0;
            m_trackers.back().source = announce_entry::source_magnet_link;
            m_torrent_file->add_tracker(p.tracker_url);
        }

        if (settings().prefer_udp_trackers)
            prioritize_udp_trackers();
    }

#if 1

    // NON BOTTLED VERSION. SUPPORTS PROGRESS REPORTING

    // since this download is not bottled, this callback will
    // be called every time we receive another piece of the
    // .torrent file
    void torrent::on_torrent_download(error_code const& ec
        , http_parser const& parser
        , char const* data, int size)
    {
        if (m_abort) return;

        if (ec && ec != asio::error::eof)
        {
            set_error(ec, m_url);
            pause();
            return;
        }

        if (size > 0)
        {
            m_torrent_file_buf.insert(m_torrent_file_buf.end(), data, data + size);
            if (parser.content_length() > 0)
                set_progress_ppm(boost::int64_t(m_torrent_file_buf.size())
                    * 1000000 / parser.content_length());
        }

        if (parser.header_finished() && parser.status_code() != 200)
        {
            set_error(error_code(parser.status_code(), get_http_category()), parser.message());
            pause();
            return;
        }

        if (!ec) return;

        std::string const& encoding = parser.header("content-encoding");
        if ((encoding == "gzip" || encoding == "x-gzip") && m_torrent_file_buf.size())
        {
            std::vector<char> buf;
            std::string error;
            if (inflate_gzip(&m_torrent_file_buf[0], m_torrent_file_buf.size()
                , buf, 4 * 1024 * 1024, error))
            {
                set_error(errors::http_failed_decompress, m_url);
                pause();
                std::vector<char>().swap(m_torrent_file_buf);
                return;
            }
            m_torrent_file_buf.swap(buf);
        }

        // we're done!
        error_code e;
        intrusive_ptr<torrent_info> tf(new torrent_info(
            &m_torrent_file_buf[0], m_torrent_file_buf.size(), e));
        if (e)
        {
            set_error(e, m_url);
            pause();
            std::vector<char>().swap(m_torrent_file_buf);
            return;
        }
        std::vector<char>().swap(m_torrent_file_buf);

        // update our torrent_info object and move the
        // torrent from the old info-hash to the new one
        // as we replace the torrent_info object
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        int num_torrents = m_ses.m_torrents.size();
#endif
        // we're about to erase the session's reference to this
        // torrent, create another reference
        boost::shared_ptr<torrent> me(shared_from_this());

        m_ses.remove_torrent_impl(me, 0);

        m_torrent_file = tf;

        // now, we might already have this torrent in the session.
        session_impl::torrent_map::iterator i = m_ses.m_torrents.find(m_torrent_file->info_hash());
        if (i != m_ses.m_torrents.end())
        {
            if (!m_uuid.empty() && i->second->uuid().empty())
                i->second->set_uuid(m_uuid);
            if (!m_url.empty() && i->second->url().empty())
                i->second->set_url(m_url);
            if (!m_source_feed_url.empty() && i->second->source_feed_url().empty())
                i->second->set_source_feed_url(m_source_feed_url);

            // insert this torrent in the uuid index
            if (!m_uuid.empty() || !m_url.empty())
            {
                m_ses.m_uuids.insert(std::make_pair(m_uuid.empty()
                    ? m_url : m_uuid, i->second));
            }
            set_error(error_code(errors::duplicate_torrent, get_libtorrent_category()), "");
            abort();
            return;
        }

        m_ses.m_torrents.insert(std::make_pair(m_torrent_file->info_hash(), me));
        if (!m_uuid.empty()) m_ses.m_uuids.insert(std::make_pair(m_uuid, me));

        TORRENT_ASSERT(num_torrents == int(m_ses.m_torrents.size()));

        // if the user added any trackers while downloading the
        // .torrent file, serge them into the new tracker list
        std::vector<announce_entry> new_trackers = m_torrent_file->trackers();
        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
        {
            // if we already have this tracker, ignore it
            if (std::find_if(new_trackers.begin(), new_trackers.end()
                , boost::bind(&announce_entry::url, _1) == i->url) != new_trackers.end())
                continue;

            // insert the tracker ordered by tier
            new_trackers.insert(std::find_if(new_trackers.begin(), new_trackers.end()
                , boost::bind(&announce_entry::tier, _1) >= i->tier), *i);
        }
        m_trackers.swap(new_trackers);

#ifndef TORRENT_DISABLE_ENCRYPTION
        hasher h;
        h.update("req2", 4);
        h.update((char*)&m_torrent_file->info_hash()[0], 20);
        m_obfuscated_hash = h.final();
#endif

        if (m_ses.m_alerts.should_post<metadata_received_alert>())
        {
            m_ses.m_alerts.post_alert(metadata_received_alert(
                get_handle()));
        }

        set_state(torrent_status::downloading);

        m_override_resume_data = true;
        init();
        announce_with_tracker();
    }
#else

    void torrent::on_torrent_download(error_code const& ec
        , http_parser const& parser, char const* data, int size)
    {
        if (m_abort) return;

        if (ec && ec != asio::error::eof)
        {
            set_error(ec, m_url);
            pause();
            return;
        }

        if (parser.status_code() != 200)
        {
            // #error there should really be an error code category for HTTP
            set_error(errors::http_error, parser.message());
            pause();
            return;
        }

        error_code e;
        intrusive_ptr<torrent_info> tf(new torrent_info(data, size, e));
        if (e)
        {
            set_error(e, m_url);
            pause();
            return;
        }

        // update our torrent_info object and move the
        // torrent from the old info-hash to the new one
        // as we replace the torrent_info object
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        int num_torrents = m_ses.m_torrents.size();
#endif
        m_ses.m_torrents.erase(m_torrent_file->info_hash());
        m_torrent_file = tf;
        m_ses.m_torrents.insert(std::make_pair(m_torrent_file->info_hash(), shared_from_this()));

        TORRENT_ASSERT(num_torrents == m_ses.m_torrents.size());

        // TODO: if the user added any trackers while downloading the
        // .torrent file, they are overwritten. Merge them into the
        // new tracker list
        m_trackers = m_torrent_file->trackers();

#ifndef TORRENT_DISABLE_ENCRYPTION
        hasher h;
        h.update("req2", 4);
        h.update((char*)&m_torrent_file->info_hash()[0], 20);
        m_obfuscated_hash = h.final();
#endif

        if (m_ses.m_alerts.should_post<metadata_received_alert>())
        {
            m_ses.m_alerts.post_alert(metadata_received_alert(
                get_handle()));
        }

        set_state(torrent_status::downloading);

        m_override_resume_data = true;
        init();
        announce_with_tracker();
    }

#endif

    void torrent::start()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
        (*m_ses.m_logger) << time_now_string() << " starting torrent: "
            << torrent_file().name() << "\n";
#endif
        TORRENT_ASSERT(!m_picker);

        if (!m_seed_mode)
        {
            m_picker.reset(new piece_picker());
            std::fill(m_file_progress.begin(), m_file_progress.end(), 0);

            if (!m_resume_data.empty())
            {
                int pos;
                error_code ec;
                if (lazy_bdecode(&m_resume_data[0], &m_resume_data[0]
                    + m_resume_data.size(), m_resume_entry, ec, &pos) != 0)
                {
                    std::vector<char>().swap(m_resume_data);
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                    (*m_ses.m_logger) << time_now_string() << " fastresume data for "
                        << torrent_file().name() << " rejected: " << ec.message()
                        << " pos: " << pos << "\n";
#endif
                    if (m_ses.m_alerts.should_post<fastresume_rejected_alert>())
                    {
                        m_ses.m_alerts.post_alert(fastresume_rejected_alert(get_handle(), ec));
                    }
                }
            }
        }

        if (!m_torrent_file->is_valid() && !m_url.empty())
        {
            // we need to download the .torrent file from m_url
            start_download_url();
        }
        else if (m_torrent_file->is_valid())
        {
            init();
        }
        else
        {
            // we need to start announcing since we don't have any
            // metadata. To receive peers to ask for it.
            set_state(torrent_status::downloading_metadata);
            start_announcing();
        }
    }

    void torrent::start_download_url()
    {
        TORRENT_ASSERT(!m_url.empty());
        TORRENT_ASSERT(!m_torrent_file->is_valid());
        boost::shared_ptr<http_connection> conn(
            new http_connection(m_ses.m_io_service, m_ses.m_half_open
                , boost::bind(&torrent::on_torrent_download, shared_from_this()
                    , _1, _2, _3, _4), false));
        conn->get(m_url, seconds(30), 0, 0, 5, m_ses.m_settings.user_agent);
        set_state(torrent_status::downloading_metadata);
    }

    void torrent::set_apply_ip_filter(bool b)
    {
        if (b == m_apply_ip_filter) return;
        if (b)
        {
            TORRENT_ASSERT(m_ses.m_non_filtered_torrents > 0);
            --m_ses.m_non_filtered_torrents;
        }
        else
        {
            ++m_ses.m_non_filtered_torrents;
        }
        m_apply_ip_filter = b;
        m_policy.ip_filter_updated();
    }

#ifndef TORRENT_DISABLE_DHT
    bool torrent::should_announce_dht() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (m_ses.m_listen_sockets.empty()) return false;

        if (!m_ses.m_dht) return false;
        if (m_torrent_file->is_valid() && !m_files_checked) return false;
        if (!m_announce_to_dht) return false;
        if (!m_allow_peers) return false;

        // if we don't have the metadata, and we're waiting
        // for a web server to serve it to us, no need to announce
        // because the info-hash is just the URL hash
        if (!m_torrent_file->is_valid() && !m_url.empty()) return false;

        // don't announce private torrents
        if (m_torrent_file->is_valid() && m_torrent_file->priv()) return false;
        if (m_trackers.empty()) return true;
        if (!settings().use_dht_as_fallback) return true;

        int verified_trackers = 0;
        for (std::vector<announce_entry>::const_iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
            if (i->verified) ++verified_trackers;

        return verified_trackers == 0;
    }

#endif

    torrent::~torrent()
    {
        if (!m_apply_ip_filter)
        {
            TORRENT_ASSERT(m_ses.m_non_filtered_torrents > 0);
            --m_ses.m_non_filtered_torrents;
            m_apply_ip_filter = true;
        }

        TORRENT_ASSERT(m_ses.is_network_thread());
        // The invariant can't be maintained here, since the torrent
        // is being destructed, all weak references to it have been
        // reset, which means that all its peers already have an
        // invalidated torrent pointer (so it cannot be verified to be correct)

        // i.e. the invariant can only be maintained if all connections have
        // been closed by the time the torrent is destructed. And they are
        // supposed to be closed. So we can still do the invariant check.

        TORRENT_ASSERT(m_connections.empty());

        INVARIANT_CHECK;

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING || defined TORRENT_LOGGING
        log_to_all_peers("DESTRUCTING TORRENT");
#endif

        TORRENT_ASSERT(m_abort);
        if (!m_connections.empty())
            disconnect_all(errors::torrent_aborted);
    }

    void torrent::read_piece(int piece)
    {
        TORRENT_ASSERT(piece >= 0 && piece < m_torrent_file->num_pieces());
        int piece_size = m_torrent_file->piece_size(piece);
        int blocks_in_piece = (piece_size + block_size() - 1) / block_size();

        // if blocks_in_piece is 0, rp will leak
        TORRENT_ASSERT(blocks_in_piece > 0);
        TORRENT_ASSERT(piece_size > 0);

        read_piece_struct* rp = new read_piece_struct;
        rp->piece_data.reset(new (std::nothrow) char[piece_size]);
        rp->blocks_left = 0;
        rp->fail = false;

        peer_request r;
        r.piece = piece;
        r.start = 0;
        for (int i = 0; i < blocks_in_piece; ++i, r.start += block_size())
        {
            r.length = (std::min)(piece_size - r.start, block_size());
            filesystem().async_read(r, boost::bind(&torrent::on_disk_read_complete
                , shared_from_this(), _1, _2, r, rp));
            ++rp->blocks_left;
        }
    }

    void torrent::send_share_mode()
    {
#ifndef TORRENT_DISABLE_EXTENSIONS
        for (std::set<peer_connection*>::iterator i = m_connections.begin()
            , end(m_connections.end()); i != end; ++i)
        {
            if ((*i)->type() != peer_connection::bittorrent_connection) continue;
            bt_peer_connection* p = (bt_peer_connection*)*i;
            p->write_share_mode();
        }
#endif
    }

    void torrent::send_upload_only()
    {
#ifndef TORRENT_DISABLE_EXTENSIONS
        if (share_mode()) return;
        if (super_seeding()) return;

        for (std::set<peer_connection*>::iterator i = m_connections.begin();
            i != m_connections.end();)
        {
            // since the call to disconnect_if_redundant() may
            // delete the entry from this container, make sure
            // to increment the iterator early
            bt_peer_connection* p = (bt_peer_connection*)*i;
            ++i;
            if (p->type() == peer_connection::bittorrent_connection)
                p->write_upload_only();
            p->disconnect_if_redundant();
        }
#endif
    }

    void torrent::set_share_mode(bool s)
    {
        if (s == m_share_mode) return;

        m_share_mode = s;

        // in share mode, all pieces have their priorities initialized to 0
        std::fill(m_file_priority.begin(), m_file_priority.end(), !m_share_mode);

        update_piece_priorities();

        if (m_share_mode) recalc_share_mode();
    }

    void torrent::set_upload_mode(bool b)
    {
        if (b == m_upload_mode) return;

        m_upload_mode = b;

        send_upload_only();

        if (m_upload_mode)
        {
            // clear request queues of all peers
            for (std::set<peer_connection*>::iterator i = m_connections.begin()
                , end(m_connections.end()); i != end; ++i)
            {
                peer_connection* p = (*i);
                p->cancel_all_requests();
            }
            // this is used to try leaving upload only mode periodically
            m_upload_mode_time = 0;
        }
        else
        {
            // reset last_connected, to force fast reconnect after leaving upload mode
            for (policy::iterator i = m_policy.begin_peer()
                , end(m_policy.end_peer()); i != end; ++i)
            {
                (*i)->last_connected = 0;
            }

            // send_block_requests on all peers
            for (std::set<peer_connection*>::iterator i = m_connections.begin()
                , end(m_connections.end()); i != end; ++i)
            {
                peer_connection* p = (*i);
                p->send_block_requests();
            }
        }
    }

    void torrent::handle_disk_error(disk_io_job const& j, peer_connection* c)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!j.error) return;

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
        (*m_ses.m_logger) << "disk error: '" << j.error.message()
            << " in file " << j.error_file
            << " in torrent " << torrent_file().name()
            << "\n";
#endif

        TORRENT_ASSERT(j.piece >= 0);

        piece_block block_finished(j.piece, j.offset / block_size());

        if (j.action == disk_io_job::write)
        {
            // we failed to write j.piece to disk tell the piece picker
            if (has_picker() && j.piece >= 0) picker().write_failed(block_finished);
        }

        if (j.error ==
#if BOOST_VERSION == 103500
            error_code(boost::system::posix_error::not_enough_memory, get_posix_category())
#elif BOOST_VERSION > 103500
            error_code(boost::system::errc::not_enough_memory, get_posix_category())
#else
            asio::error::no_memory
#endif
            )
        {
            if (alerts().should_post<file_error_alert>())
                alerts().post_alert(file_error_alert(j.error_file, get_handle(), j.error));
            if (c) c->disconnect(errors::no_memory);
            return;
        }

        // notify the user of the error
        if (alerts().should_post<file_error_alert>())
            alerts().post_alert(file_error_alert(j.error_file, get_handle(), j.error));

        // put the torrent in an error-state
        set_error(j.error, j.error_file);

        if (j.action == disk_io_job::write
            && (j.error == boost::system::errc::read_only_file_system
            || j.error == boost::system::errc::permission_denied
            || j.error == boost::system::errc::operation_not_permitted
            || j.error == boost::system::errc::no_space_on_device
            || j.error == boost::system::errc::file_too_large))
        {
            // if we failed to write, stop downloading and just
            // keep seeding.
            // TODO: make this depend on the error and on the filesystem the
            // files are being downloaded to. If the error is no_space_left_on_device
            // and the filesystem doesn't support sparse files, only zero the priorities
            // of the pieces that are at the tails of all files, leaving everything
            // up to the highest written piece in each file
            set_upload_mode(true);
            return;
        }

        // if the error appears to be more serious than a full disk, just pause the torrent
        pause();
    }

    void torrent::on_disk_read_complete(int ret, disk_io_job const& j, peer_request r, read_piece_struct* rp)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        disk_buffer_holder buffer(m_ses, j.buffer);

        --rp->blocks_left;
        if (ret != r.length)
        {
            rp->fail = true;
            handle_disk_error(j);
        }
        else
        {
            std::memcpy(rp->piece_data.get() + r.start, j.buffer, r.length);
        }

        if (rp->blocks_left == 0)
        {
            int size = m_torrent_file->piece_size(r.piece);
            if (rp->fail)
            {
                rp->piece_data.reset();
                size = 0;
            }

            if (m_ses.m_alerts.should_post<read_piece_alert>())
            {
                m_ses.m_alerts.post_alert(read_piece_alert(
                    get_handle(), r.piece, rp->piece_data, size));
            }
            delete rp;
        }
    }

    void torrent::add_piece(int piece, char const* data, int flags)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(piece >= 0 && piece < m_torrent_file->num_pieces());
        int piece_size = m_torrent_file->piece_size(piece);
        int blocks_in_piece = (piece_size + block_size() - 1) / block_size();

        // avoid crash trying to access the picker when there is none
        if (is_seed()) return;

        if (picker().have_piece(piece)
            && (flags & torrent::overwrite_existing) == 0)
            return;

        peer_request p;
        p.piece = piece;
        p.start = 0;
        picker().inc_refcount(piece);
        for (int i = 0; i < blocks_in_piece; ++i, p.start += block_size())
        {
            if (picker().is_finished(piece_block(piece, i))
                && (flags & torrent::overwrite_existing) == 0)
                continue;

            p.length = (std::min)(piece_size - p.start, int(block_size()));
            char* buffer = m_ses.allocate_disk_buffer("add piece");
            // out of memory
            if (buffer == 0)
            {
                picker().dec_refcount(piece);
                return;
            }
            disk_buffer_holder holder(m_ses, buffer);
            std::memcpy(buffer, data + p.start, p.length);
            filesystem().async_write(p, holder, boost::bind(&torrent::on_disk_write_complete
                , shared_from_this(), _1, _2, p));
            piece_block block(piece, i);
            picker().mark_as_downloading(block, 0, piece_picker::fast);
            picker().mark_as_writing(block, 0);
        }
        async_verify_piece(piece, boost::bind(&torrent::piece_finished
            , shared_from_this(), piece, _1));
        picker().dec_refcount(piece);
    }

    void torrent::on_disk_write_complete(int ret, disk_io_job const& j
        , peer_request p)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

        if (is_seed()) return;

        if (m_abort)
        {
            piece_block block_finished(p.piece, p.start / block_size());
            return;
        }

        piece_block block_finished(p.piece, p.start / block_size());

        if (ret == -1)
        {
            handle_disk_error(j);
            return;
        }

        // if we already have this block, just ignore it.
        // this can happen if the same block is passed in through
        // add_piece() multiple times
        if (picker().is_finished(block_finished)) return;

        picker().mark_as_finished(block_finished, 0);
    }

    void torrent::on_disk_cache_complete(int ret, disk_io_job const& j)
    {
        // suggest this piece to all peers
        for (peer_iterator i = m_connections.begin();
            i != m_connections.end(); ++i)
            (*i)->send_suggest(j.piece);
    }

    bool torrent::add_merkle_nodes(std::map<int, sha1_hash> const& nodes, int piece)
    {
        return m_torrent_file->add_merkle_nodes(nodes, piece);
    }

    peer_request torrent::to_req(piece_block const& p) const
    {
        int block_offset = p.block_index * block_size();
        int block = (std::min)(torrent_file().piece_size(
            p.piece_index) - block_offset, int(block_size()));
        TORRENT_ASSERT(block > 0);
        TORRENT_ASSERT(block <= block_size());

        peer_request r;
        r.piece = p.piece_index;
        r.start = block_offset;
        r.length = block;
        return r;
    }

    std::string torrent::name() const
    {
        if (valid_metadata()) return m_torrent_file->name();
        if (m_name) return *m_name;
        return "";
    }

#ifndef TORRENT_DISABLE_EXTENSIONS

    void torrent::add_extension(boost::shared_ptr<torrent_plugin> ext)
    {
        m_extensions.push_back(ext);
    }

    void torrent::add_extension(boost::function<boost::shared_ptr<torrent_plugin>(torrent*, void*)> const& ext
        , void* userdata)
    {
        boost::shared_ptr<torrent_plugin> tp(ext(this, userdata));
        if (!tp) return;

        add_extension(tp);

        for (peer_iterator i = m_connections.begin();
            i != m_connections.end(); ++i)
        {
            peer_connection* p = *i;
            boost::shared_ptr<peer_plugin> pp(tp->new_connection(p));
            if (pp) p->add_extension(pp);
        }

        // if files are checked for this torrent, call the extension
        // to let it initialize itself
        if (m_connections_initialized)
            tp->on_files_checked();
    }

#endif

#ifdef TORRENT_USE_OPENSSL
/*
    bool verify_function(bool preverified, boost::asio::ssl::verify_context& ctx)
    {
        return false;
    }
*/

    void torrent::init_ssl(std::string const& cert)
    {
        using boost::asio::ssl::context;

        // this is needed for openssl < 1.0 to decrypt keys created by openssl 1.0+
        OpenSSL_add_all_algorithms();

        // TODO: come up with something better
        RAND_seed(&info_hash()[0], 20);
        TORRENT_ASSERT(RAND_status() == 1);

        // create the SSL context for this torrent. We need to
        // inject the root certificate, and no other, to
        // verify other peers against
        boost::shared_ptr<context> ctx(
            new (std::nothrow) context(m_ses.m_io_service, context::sslv23));

        if (!ctx)
        {
            set_error(asio::error::no_memory, "SSL context");
            pause();
            return;
        }

        ctx->set_options(context::default_workarounds
            | boost::asio::ssl::context::no_sslv2
            | boost::asio::ssl::context::single_dh_use);

        error_code ec;
        ctx->set_verify_mode(context::verify_peer
            | context::verify_fail_if_no_peer_cert
            | context::verify_client_once, ec);
        if (ec)
        {
            set_error(ec, "SSL verify mode");
            pause();
            return;
        }

        // this is used for debugging
        /*
#error there's a bug where the async_handshake on the ssl_stream always succeeds, regardless of the certificate failing. It's not a trivial bug in asio, that's been tested with a small repro program.
ctx->set_verify_callback(verify_function, ec);
        if (ec)
        {
            set_error(ec, "SSL verify callback");
            pause();
            return;
        }
        */
        SSL_CTX* ssl_ctx = ctx->impl();

        // create a new x.509 certificate store
        X509_STORE* cert_store = X509_STORE_new();
        if (!cert_store)
        {
            set_error(asio::error::no_memory, "x.509 certificate store");
            pause();
            return;
        }

        // wrap the PEM certificate in a BIO, for openssl to read
        BIO* bp = BIO_new_mem_buf((void*)cert.c_str(), cert.size());

        // parse the certificate into OpenSSL's internal
        // representation
        X509* certificate = PEM_read_bio_X509_AUX(bp, 0, 0, 0);

        BIO_free(bp);

        if (!certificate)
        {
            X509_STORE_free(cert_store);
            set_error(asio::error::no_memory, "x.509 certificate");
            pause();
            return;
        }

        // add cert to cert_store
        X509_STORE_add_cert(cert_store, certificate);

        // and lastly, replace the default cert store with ours
        SSL_CTX_set_cert_store(ssl_ctx, cert_store);
#if 0
        char filename[100];
        snprintf(filename, sizeof(filename), "/tmp/%d.pem", rand());
        FILE* f = fopen(filename, "w+");
        fwrite(cert.c_str(), cert.size(), 1, f);
        fclose(f);
        ctx->load_verify_file(filename);
#endif
        // if all went well, set the torrent ssl context to this one
        m_ssl_ctx = ctx;

        // tell the client we need a cert for this torrent
        alerts().post_alert(torrent_need_cert_alert(get_handle()));

        m_ssl_acceptor.reset(new listen_socket_t);
        m_ses.setup_listener(m_ssl_acceptor.get()
            , tcp::endpoint(address_v4::any(), m_ses.m_listen_interface.port())
            , m_ses.m_listen_port_retries + 10, false, 0, ec);
        if (!m_ssl_acceptor->sock)
        {
            set_error(ec, "ssl listen port");
            pause();
            return;
        }

        // TODO: issue UPnP and NAT-PMP for this socket

        async_accept(m_ssl_acceptor->sock);

        set_allow_peers(false);
    }

    void torrent::async_accept(boost::shared_ptr<socket_acceptor> const& listener)
    {
        boost::shared_ptr<socket_type> c(new socket_type(m_ses.m_io_service));
        c->instantiate<ssl_stream<stream_socket> >(m_ses.m_io_service, m_ssl_ctx.get());

#if defined TORRENT_ASIO_DEBUGGING
        add_outstanding_async("torrent::on_accept_ssl_connection");
#endif
        listener->async_accept(c->get<ssl_stream<stream_socket> >()->next_layer()
            , boost::bind(&torrent::on_accept_ssl_connection, shared_from_this(), c
                , boost::weak_ptr<socket_acceptor>(listener), _1));
    }

    void torrent::on_accept_ssl_connection(boost::shared_ptr<socket_type> const& s
        , boost::weak_ptr<socket_acceptor> listen_socket, error_code const& e)
    {
#if defined TORRENT_ASIO_DEBUGGING
        complete_async("torrent::on_accept_ssl_connection");
#endif
        // TODO: there's some code duplication with session_impl::on_accept_connection

        boost::shared_ptr<socket_acceptor> listener = listen_socket.lock();
        if (!listener) return;

        if (e == asio::error::operation_aborted) return;

        if (m_abort) return;

        error_code ec;
        if (e)
        {
            tcp::endpoint ep = listener->local_endpoint(ec);
#if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING)
            std::string msg = "error accepting connection on '"
                + print_endpoint(ep) + "' " + e.message();
            (*m_ses.m_logger) << msg << "\n";
#endif
#ifdef TORRENT_WINDOWS
            // Windows sometimes generates this error. It seems to be
            // non-fatal and we have to do another async_accept.
            if (e.value() == ERROR_SEM_TIMEOUT)
            {
                async_accept(listener);
                return;
            }
#endif
#ifdef TORRENT_BSD
            // Leopard sometimes generates an "invalid argument" error. It seems to be
            // non-fatal and we have to do another async_accept.
            if (e.value() == EINVAL)
            {
                async_accept(listener);
                return;
            }
#endif
            if (alerts().should_post<listen_failed_alert>())
                alerts().post_alert(listen_failed_alert(ep, e));
            return;
        }
        async_accept(listener);

        if (is_paused()) return;

        // we got a connection request!
        tcp::endpoint endp = s->remote_endpoint(ec);

        if (ec)
        {
#if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING)
            (*m_ses.m_logger) << endp << " <== INCOMING CONNECTION FAILED, could "
                "not retrieve remote endpoint " << ec.message() << "\n";
#endif
            return;
        }

        if (alerts().should_post<incoming_connection_alert>())
        {
            alerts().post_alert(incoming_connection_alert(s->type(), endp));
        }

        if (!settings().enable_incoming_tcp)
        {
            if (alerts().should_post<peer_blocked_alert>())
                alerts().post_alert(peer_blocked_alert(torrent_handle(), endp.address()));
            return;
        }

        if (m_apply_ip_filter
            && m_ses.m_ip_filter.access(endp.address()) & ip_filter::blocked)
        {
#if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING)
            (*m_ses.m_logger) << "filtered blocked ip\n";
#endif
            if (alerts().should_post<peer_blocked_alert>())
                alerts().post_alert(peer_blocked_alert(get_handle(), endp.address()));
            return;
        }

        if (m_connections.size() >= m_max_connections)
        {
            if (alerts().should_post<peer_disconnected_alert>())
            {
                alerts().post_alert(
                    peer_disconnected_alert(get_handle(), endp, peer_id()
                        , error_code(errors::too_many_connections, get_libtorrent_category())));
            }
            return;
        }

        m_ses.setup_socket_buffers(*s);

        s->get<ssl_stream<stream_socket> >()->async_accept_handshake(boost::bind(&torrent::ssl_handshake
            , shared_from_this(), _1, s));
    }

    void torrent::ssl_handshake(error_code const& ec, boost::shared_ptr<socket_type> s)
    {
        error_code e;
        tcp::endpoint endp = s->remote_endpoint(e);
        if (e) return;

#if defined(TORRENT_VERBOSE_LOGGING) || defined(TORRENT_LOGGING)
        (*m_ses.m_logger) << time_now_string() << " *** peer SSL handshake done [ ip: "
            << endp << " ec: " << ec.message() << "]\n";
#endif

        if (ec)
        {
            if (alerts().should_post<peer_error_alert>())
            {
                alerts().post_alert(peer_error_alert(get_handle(), endp
                    , peer_id(), ec));
            }
            return;
        }

        boost::intrusive_ptr<peer_connection> c(
            new bt_peer_connection(m_ses, shared_from_this(), s, endp, 0, false));
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        c->m_in_constructor = false;
#endif

        if (c->is_disconnecting()) return;

        if (!m_policy.new_connection(*c, m_ses.session_time()))
        {
#if defined TORRENT_LOGGING
            (*m_ses.m_logger) << time_now_string() << " CLOSING CONNECTION "
                << c->remote() << " policy::new_connection returned false (i.e. peer list full)\n";
#endif
            c->disconnect(errors::too_many_connections);
            return;
        }

        // add the newly connected peer to this torrent's peer list
        m_connections.insert(boost::get_pointer(c));
        m_ses.m_connections.insert(c);
        c->start();
        if (settings().default_peer_upload_rate)
            c->set_upload_limit(settings().default_peer_upload_rate);
        if (settings().default_peer_download_rate)
            c->set_download_limit(settings().default_peer_download_rate);
    }

#endif

    // this may not be called from a constructor because of the call to
    // shared_from_this()
    void torrent::init()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(m_torrent_file->is_valid());
        TORRENT_ASSERT(m_torrent_file->num_files() > 0);
        TORRENT_ASSERT(m_torrent_file->total_size() >= 0);

#ifdef TORRENT_USE_OPENSSL
        std::string cert = m_torrent_file->ssl_cert();
        if (!cert.empty()) init_ssl(cert);
#endif

#ifdef TORRENT_USE_OPENSSL
        if (m_torrent_file->encryption_key().size() == 32 && !m_in_encrypted_list)
        {
            m_ses.m_encrypted_torrents.insert(shared_from_this());
            m_in_encrypted_list = true;
        }
#endif

        m_file_priority.resize(m_torrent_file->num_files(), 1);
        m_file_progress.resize(m_torrent_file->num_files(), 0);

        m_block_size_shift = root2((std::min)(int(block_size()), m_torrent_file->piece_length()));

        if (m_torrent_file->num_pieces() > piece_picker::max_pieces)
        {
            set_error(errors::too_many_pieces_in_torrent, "");
            pause();
            return;
        }

        if (m_torrent_file->num_pieces() == 0)
        {
            set_error(errors::torrent_invalid_length, "");
            pause();
            return;
        }

        // the shared_from_this() will create an intentional
        // cycle of ownership, se the hpp file for description.
        m_owning_storage = new piece_manager(shared_from_this(), m_torrent_file
            , m_save_path, m_ses.m_files, m_ses.m_disk_thread, m_storage_constructor
            , (storage_mode_t)m_storage_mode, m_file_priority);
        m_storage = m_owning_storage.get();

        if (has_picker())
        {
            int blocks_per_piece = (m_torrent_file->piece_length() + block_size() - 1) / block_size();
            int blocks_in_last_piece = ((m_torrent_file->total_size() % m_torrent_file->piece_length())
                + block_size() - 1) / block_size();
            m_picker->init(blocks_per_piece, blocks_in_last_piece, m_torrent_file->num_pieces());
        }

        if (m_share_mode)
        {
            // in share mode, all pieces have their priorities initialized to 0
            std::fill(m_file_priority.begin(), m_file_priority.end(), 0);
        }

        // in case file priorities were passed in via the add_torrent_params
        // ans also in the case of share mode, we need to update the priorities
        update_piece_priorities();

        std::vector<web_seed_entry> const& web_seeds = m_torrent_file->web_seeds();
        m_web_seeds.insert(m_web_seeds.end(), web_seeds.begin(), web_seeds.end());

        if (m_seed_mode)
        {
            m_ses.m_io_service.post(boost::bind(&torrent::files_checked, shared_from_this()));
            std::vector<char>().swap(m_resume_data);
            lazy_entry().swap(m_resume_entry);
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
            m_resume_data_loaded = true;
#endif
            return;
        }

        set_state(torrent_status::checking_resume_data);

        if (m_resume_entry.type() == lazy_entry::dict_t)
        {
            int ev = 0;
            if (m_resume_entry.dict_find_string_value("file-format") != "libtorrent resume file")
                ev = errors::invalid_file_tag;

            std::string info_hash = m_resume_entry.dict_find_string_value("info-hash");
            if (!ev && info_hash.empty())
                ev = errors::missing_info_hash;

            if (!ev && sha1_hash(info_hash) != m_torrent_file->info_hash())
                ev = errors::mismatching_info_hash;

            if (ev && m_ses.m_alerts.should_post<fastresume_rejected_alert>())
            {
                m_ses.m_alerts.post_alert(fastresume_rejected_alert(get_handle()
                    , error_code(ev, get_libtorrent_category())));
            }

            if (ev)
            {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                (*m_ses.m_logger) << time_now_string() << " fastresume data for "
                    << torrent_file().name() << " rejected: "
                    << error_code(ev, get_libtorrent_category()).message() << "\n";
#endif
                std::vector<char>().swap(m_resume_data);
                lazy_entry().swap(m_resume_entry);
            }
            else
            {
                read_resume_data(m_resume_entry);
            }
        }

#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        m_resume_data_loaded = true;
#endif

        TORRENT_ASSERT(block_size() > 0);
        int file = 0;
        for (file_storage::iterator i = m_torrent_file->files().begin()
            , end(m_torrent_file->files().end()); i != end; ++i, ++file)
        {
            if (!i->pad_file || i->size == 0) continue;
            m_padding += i->size;

            peer_request pr = m_torrent_file->map_file(file, 0, m_torrent_file->file_at(file).size);
            int off = pr.start & (block_size()-1);
            if (off != 0) { pr.length -= block_size() - off; pr.start += block_size() - off; }
            TORRENT_ASSERT((pr.start & (block_size()-1)) == 0);

            int block = block_size();
            int blocks_per_piece = m_torrent_file->piece_length() / block;
            piece_block pb(pr.piece, pr.start / block);
            for (; pr.length >= block; pr.length -= block, ++pb.block_index)
            {
                if (int(pb.block_index) == blocks_per_piece) { pb.block_index = 0; ++pb.piece_index; }
                m_picker->mark_as_finished(pb, 0);
            }
            // ugly edge case where padfiles are not used they way they're
            // supposed to be. i.e. added back-to back or at the end
            if (int(pb.block_index) == blocks_per_piece) { pb.block_index = 0; ++pb.piece_index; }
            if (pr.length > 0 && ((boost::next(i) != end && boost::next(i)->pad_file)
                || boost::next(i) == end))
            {
                m_picker->mark_as_finished(pb, 0);
            }
        }

        if (m_padding > 0)
        {
            // if we marked an entire piece as finished, we actually
            // need to consider it finished

            std::vector<piece_picker::downloading_piece> const& dq
                = m_picker->get_download_queue();

            std::vector<int> have_pieces;

            for (std::vector<piece_picker::downloading_piece>::const_iterator i
                = dq.begin(); i != dq.end(); ++i)
            {
                int num_blocks = m_picker->blocks_in_piece(i->index);
                if (i->finished < num_blocks) continue;
                have_pieces.push_back(i->index);
            }

            for (std::vector<int>::iterator i = have_pieces.begin();
                i != have_pieces.end(); ++i)
            {
                we_have(*i);
            }
        }

        m_storage->async_check_fastresume(&m_resume_entry
            , boost::bind(&torrent::on_resume_data_checked
            , shared_from_this(), _1, _2));
    }

    bt_peer_connection* torrent::find_introducer(tcp::endpoint const& ep) const
    {
#ifndef TORRENT_DISABLE_EXTENSIONS
        for (const_peer_iterator i = m_connections.begin(); i != m_connections.end(); ++i)
        {
            if ((*i)->type() != peer_connection::bittorrent_connection) continue;
            bt_peer_connection* p = (bt_peer_connection*)(*i);
            if (!p->supports_holepunch()) continue;
            peer_plugin const* pp = p->find_plugin("ut_pex");
            if (!pp) continue;
            if (was_introduced_by(pp, ep)) return (bt_peer_connection*)p;
        }
#endif
        return 0;
    }

    bt_peer_connection* torrent::find_peer(tcp::endpoint const& ep) const
    {
        for (const_peer_iterator i = m_connections.begin(); i != m_connections.end(); ++i)
        {
            peer_connection* p = *i;
            if (p->type() != peer_connection::bittorrent_connection) continue;
            if (p->remote() == ep) return (bt_peer_connection*)p;
        }
        return 0;
    }

    void torrent::on_resume_data_checked(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (ret == piece_manager::fatal_disk_error)
        {
            handle_disk_error(j);
            set_state(torrent_status::queued_for_checking);
            std::vector<char>().swap(m_resume_data);
            lazy_entry().swap(m_resume_entry);
            return;
        }

        if (m_resume_entry.type() == lazy_entry::dict_t)
        {
            using namespace libtorrent::detail; // for read_*_endpoint()
            peer_id id(0);

            if (lazy_entry const* peers_entry = m_resume_entry.dict_find_string("peers"))
            {
                int num_peers = peers_entry->string_length() / (sizeof(address_v4::bytes_type) + 2);
                char const* ptr = peers_entry->string_ptr();
                for (int i = 0; i < num_peers; ++i)
                {
                    m_policy.add_peer(read_v4_endpoint<tcp::endpoint>(ptr)
                        , id, peer_info::resume_data, 0);
                }
            }

            if (lazy_entry const* banned_peers_entry = m_resume_entry.dict_find_string("banned_peers"))
            {
                int num_peers = banned_peers_entry->string_length() / (sizeof(address_v4::bytes_type) + 2);
                char const* ptr = banned_peers_entry->string_ptr();
                for (int i = 0; i < num_peers; ++i)
                {
                    policy::peer* p = m_policy.add_peer(read_v4_endpoint<tcp::endpoint>(ptr)
                        , id, peer_info::resume_data, 0);
                    if (p) m_policy.ban_peer(p);
                }
            }

#if TORRENT_USE_IPV6
            if (lazy_entry const* peers6_entry = m_resume_entry.dict_find_string("peers6"))
            {
                int num_peers = peers6_entry->string_length() / (sizeof(address_v6::bytes_type) + 2);
                char const* ptr = peers6_entry->string_ptr();
                for (int i = 0; i < num_peers; ++i)
                {
                    m_policy.add_peer(read_v6_endpoint<tcp::endpoint>(ptr)
                        , id, peer_info::resume_data, 0);
                }
            }

            if (lazy_entry const* banned_peers6_entry = m_resume_entry.dict_find_string("banned_peers6"))
            {
                int num_peers = banned_peers6_entry->string_length() / (sizeof(address_v6::bytes_type) + 2);
                char const* ptr = banned_peers6_entry->string_ptr();
                for (int i = 0; i < num_peers; ++i)
                {
                    policy::peer* p = m_policy.add_peer(read_v6_endpoint<tcp::endpoint>(ptr)
                        , id, peer_info::resume_data, 0);
                    if (p) m_policy.ban_peer(p);
                }
            }
#endif

            // parse out "peers" from the resume data and add them to the peer list
            if (lazy_entry const* peers_entry = m_resume_entry.dict_find_list("peers"))
            {
                for (int i = 0; i < peers_entry->list_size(); ++i)
                {
                    lazy_entry const* e = peers_entry->list_at(i);
                    if (e->type() != lazy_entry::dict_t) continue;
                    std::string ip = e->dict_find_string_value("ip");
                    int port = e->dict_find_int_value("port");
                    if (ip.empty() || port == 0) continue;
                    error_code ec;
                    tcp::endpoint a(address::from_string(ip, ec), (unsigned short)port);
                    if (ec) continue;
                    m_policy.add_peer(a, id, peer_info::resume_data, 0);
                }
            }

            // parse out "banned_peers" and add them as banned
            if (lazy_entry const* banned_peers_entry = m_resume_entry.dict_find_list("banned_peers"))
            {
                for (int i = 0; i < banned_peers_entry->list_size(); ++i)
                {
                    lazy_entry const* e = banned_peers_entry->list_at(i);
                    if (e->type() != lazy_entry::dict_t) continue;
                    std::string ip = e->dict_find_string_value("ip");
                    int port = e->dict_find_int_value("port");
                    if (ip.empty() || port == 0) continue;
                    error_code ec;
                    tcp::endpoint a(address::from_string(ip, ec), (unsigned short)port);
                    if (ec) continue;
                    policy::peer* p = m_policy.add_peer(a, id, peer_info::resume_data, 0);
                    if (p) m_policy.ban_peer(p);
                }
            }
        }

        // only report this error if the user actually provided resume data
        if ((j.error || ret != 0) && !m_resume_data.empty()
            && m_ses.m_alerts.should_post<fastresume_rejected_alert>())
        {
            m_ses.m_alerts.post_alert(fastresume_rejected_alert(get_handle(), j.error));
        }

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
        (*m_ses.m_logger) << time_now_string() << " fastresume data for "
            << torrent_file().name() << " rejected: "
            << j.error.message() << " ret:" << ret << "\n";
#endif

        // if ret != 0, it means we need a full check. We don't necessarily need
        // that when the resume data check fails. For instance, if the resume data
        // is incorrect, but we don't have any files, we skip the check and initialize
        // the storage to not have anything.
        if (ret == 0)
        {
            // there are either no files for this torrent
            // or the resume_data was accepted

            if (!j.error && m_resume_entry.type() == lazy_entry::dict_t)
            {
                // parse have bitmask
                lazy_entry const* pieces = m_resume_entry.dict_find("pieces");
                if (pieces && pieces->type() == lazy_entry::string_t
                    && int(pieces->string_length()) == m_torrent_file->num_pieces())
                {
                    char const* pieces_str = pieces->string_ptr();
                    for (int i = 0, end(pieces->string_length()); i < end; ++i)
                    {
                        if (pieces_str[i] & 1) we_have(i);
                        if (m_seed_mode && (pieces_str[i] & 2)) m_verified.set_bit(i);
                    }
                }
                else
                {
                    lazy_entry const* slots = m_resume_entry.dict_find("slots");
                    if (slots && slots->type() == lazy_entry::list_t)
                    {
                        for (int i = 0; i < slots->list_size(); ++i)
                        {
                            int piece = slots->list_int_value_at(i, -1);
                            if (piece >= 0) we_have(piece);
                        }
                    }
                }

                // parse unfinished pieces
                int num_blocks_per_piece =
                    static_cast<int>(torrent_file().piece_length()) / block_size();

                if (lazy_entry const* unfinished_ent = m_resume_entry.dict_find_list("unfinished"))
                {
                    for (int i = 0; i < unfinished_ent->list_size(); ++i)
                    {
                        lazy_entry const* e = unfinished_ent->list_at(i);
                        if (e->type() != lazy_entry::dict_t) continue;
                        int piece = e->dict_find_int_value("piece", -1);
                        if (piece < 0 || piece > torrent_file().num_pieces()) continue;

                        if (m_picker->have_piece(piece))
                            m_picker->we_dont_have(piece);

                        std::string bitmask = e->dict_find_string_value("bitmask");
                        if (bitmask.empty()) continue;

                        const int num_bitmask_bytes = (std::max)(num_blocks_per_piece / 8, 1);
                        if ((int)bitmask.size() != num_bitmask_bytes) continue;
                        for (int k = 0; k < num_bitmask_bytes; ++k)
                        {
                            unsigned char bits = bitmask[k];
                            int num_bits = (std::min)(num_blocks_per_piece - k*8, 8);
                            for (int b = 0; b < num_bits; ++b)
                            {
                                const int block = k * 8 + b;
                                if (bits & (1 << b))
                                {
                                    m_picker->mark_as_finished(piece_block(piece, block), 0);
                                    if (m_picker->is_piece_finished(piece))
                                        async_verify_piece(piece, boost::bind(&torrent::piece_finished
                                            , shared_from_this(), piece, _1));
                                }
                            }
                        }
                    }
                }
            }

            files_checked();
        }
        else
        {
            // either the fastresume data was rejected or there are
            // some files
            set_state(torrent_status::queued_for_checking);
            if (should_check_files())
                queue_torrent_check();
        }

        std::vector<char>().swap(m_resume_data);
        lazy_entry().swap(m_resume_entry);
    }

    void torrent::queue_torrent_check()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (m_queued_for_checking) return;
        m_queued_for_checking = true;
        m_ses.queue_check_torrent(shared_from_this());
    }

    void torrent::dequeue_torrent_check()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!m_queued_for_checking) return;
        m_queued_for_checking = false;
        m_ses.dequeue_check_torrent(shared_from_this());
    }

    void torrent::force_recheck()
    {
        if (!valid_metadata()) return;

        // if the torrent is already queued to check its files
        // don't do anything
        if (should_check_files()
            || m_state == torrent_status::checking_resume_data)
            return;

        clear_error();

        disconnect_all(errors::stopping_torrent);
        stop_announcing();

        m_owning_storage->async_release_files();
        if (!m_picker) m_picker.reset(new piece_picker());
        std::fill(m_file_progress.begin(), m_file_progress.end(), 0);

        int blocks_per_piece = (m_torrent_file->piece_length() + block_size() - 1) / block_size();
        int blocks_in_last_piece = ((m_torrent_file->total_size() % m_torrent_file->piece_length())
            + block_size() - 1) / block_size();
        m_picker->init(blocks_per_piece, blocks_in_last_piece, m_torrent_file->num_pieces());
        // assume that we don't have anything
        TORRENT_ASSERT(m_picker->num_have() == 0);
        m_files_checked = false;
        set_state(torrent_status::checking_resume_data);

        m_policy.recalculate_connect_candidates();

        if (m_auto_managed && !is_finished())
            set_queue_position((std::numeric_limits<int>::max)());

        std::vector<char>().swap(m_resume_data);
        lazy_entry().swap(m_resume_entry);
        m_storage->async_check_fastresume(&m_resume_entry
            , boost::bind(&torrent::on_force_recheck
            , shared_from_this(), _1, _2));
    }

    void torrent::on_force_recheck(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (ret == piece_manager::fatal_disk_error)
        {
            handle_disk_error(j);
            return;
        }
        if (ret == 0)
        {
            // if there are no files, just start
            files_checked();
        }
        else
        {
            set_state(torrent_status::queued_for_checking);
            if (should_check_files())
                queue_torrent_check();
        }
    }

    void torrent::start_checking()
    {
        TORRENT_ASSERT(should_check_files());
        set_state(torrent_status::checking_files);

        m_storage->async_check_files(boost::bind(
            &torrent::on_piece_checked
            , shared_from_this(), _1, _2));
    }

    void torrent::on_piece_checked(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (ret == piece_manager::disk_check_aborted)
        {
            dequeue_torrent_check();
            pause();
            return;
        }
        if (ret == piece_manager::fatal_disk_error)
        {
            if (m_ses.m_alerts.should_post<file_error_alert>())
            {
                m_ses.m_alerts.post_alert(file_error_alert(j.error_file, get_handle(), j.error));
            }
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
            (*m_ses.m_logger) << time_now_string() << ": fatal disk error ["
                " error: " << j.error.message() <<
                " torrent: " << torrent_file().name() <<
                " ]\n";
#endif
            pause();
            set_error(j.error, j.error_file);
            return;
        }

        m_progress_ppm = size_type(j.piece) * 1000000 / torrent_file().num_pieces();

        TORRENT_ASSERT(m_picker);
        if (j.offset >= 0 && !m_picker->have_piece(j.offset))
        {
            we_have(j.offset);
            remove_time_critical_piece(j.offset);
        }

        // we're not done checking yet
        // this handler will be called repeatedly until
        // we're done, or encounter a failure
        if (ret == piece_manager::need_full_check) return;

        dequeue_torrent_check();
        files_checked();
    }

    void torrent::use_interface(std::string net_interfaces)
    {
        INVARIANT_CHECK;
        m_net_interfaces.clear();

        char* str = &net_interfaces[0];

        while (str)
        {
            char* space = strchr(str, ',');
            if (space) *space++ = 0;
            error_code ec;
            address a(address::from_string(str, ec));
            str = space;
            if (ec) continue;
            m_net_interfaces.push_back(tcp::endpoint(a, 0));
        }
    }

    tcp::endpoint torrent::get_interface() const
    {
        if (m_net_interfaces.empty()) return tcp::endpoint(address_v4(), 0);
        if (m_interface_index >= m_net_interfaces.size()) m_interface_index = 0;
        return m_net_interfaces[m_interface_index++];
    }

    void torrent::on_tracker_announce_disp(boost::weak_ptr<torrent> p
        , error_code const& e)
    {
#if defined TORRENT_ASIO_DEBUGGING
        complete_async("tracker::on_tracker_announce_disp");
#endif
        if (e) return;
        boost::shared_ptr<torrent> t = p.lock();
        if (!t) return;
        t->on_tracker_announce();
    }

    void torrent::on_tracker_announce()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        m_waiting_tracker = false;
        if (m_abort) return;
        announce_with_tracker();
    }

    void torrent::lsd_announce()
    {
        if (m_abort) return;

        // if the files haven't been checked yet, we're
        // not ready for peers
        if (!m_files_checked) return;

        if (!m_announce_to_lsd) return;

        if (m_torrent_file->is_valid()
            && (m_torrent_file->priv()
                || (torrent_file().is_i2p()
                    && !settings().allow_i2p_mixed)))
            return;

        if (is_paused()) return;

#ifdef TORRENT_USE_OPENSSL
        int port = is_ssl_torrent() ? m_ssl_acceptor->external_port : m_ses.listen_port();
#else
        int port = m_ses.listen_port();
#endif

        // announce with the local discovery service
        m_ses.announce_lsd(m_torrent_file->info_hash(), port
            , m_ses.settings().broadcast_lsd && m_lsd_seq == 0);
        ++m_lsd_seq;
    }

#ifndef TORRENT_DISABLE_DHT

    void torrent::dht_announce()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!m_ses.m_dht) return;
        if (!should_announce_dht()) return;

        TORRENT_ASSERT(m_allow_peers);

#ifdef TORRENT_USE_OPENSSL
        int port = is_ssl_torrent() ? m_ssl_acceptor->external_port : m_ses.listen_port();
#else
        int port = m_ses.listen_port();
#endif

        boost::weak_ptr<torrent> self(shared_from_this());
        m_ses.m_dht->announce(m_torrent_file->info_hash()
            , port, is_seed()
            , boost::bind(&torrent::on_dht_announce_response_disp, self, _1));
    }

    void torrent::on_dht_announce_response_disp(boost::weak_ptr<libtorrent::torrent> t
        , std::vector<tcp::endpoint> const& peers)
    {
        boost::shared_ptr<libtorrent::torrent> tor = t.lock();
        if (!tor) return;
        tor->on_dht_announce_response(peers);
    }

    void torrent::on_dht_announce_response(std::vector<tcp::endpoint> const& peers)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (peers.empty()) return;

        if (m_ses.m_alerts.should_post<dht_reply_alert>())
        {
            m_ses.m_alerts.post_alert(dht_reply_alert(
                get_handle(), peers.size()));
        }

        if (torrent_file().priv() || (torrent_file().is_i2p()
            && !settings().allow_i2p_mixed)) return;

        std::for_each(peers.begin(), peers.end(), boost::bind(
            &policy::add_peer, boost::ref(m_policy), _1, peer_id(0)
            , peer_info::dht, 0));
    }

#endif

    void torrent::announce_with_tracker(tracker_request::event_t e
        , address const& bind_interface)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (m_trackers.empty()) return;

        if (m_abort) e = tracker_request::stopped;

        // if we're not announcing to trackers, only allow
        // stopping
        if (e != tracker_request::stopped && !m_announce_to_trackers) return;

        TORRENT_ASSERT(m_allow_peers || e == tracker_request::stopped);

        if (e == tracker_request::none && is_finished() && !is_seed())
            e = tracker_request::paused;

        tracker_request req;
        req.apply_ip_filter = m_apply_ip_filter && m_ses.m_settings.apply_ip_filter_to_trackers;
        req.info_hash = m_torrent_file->info_hash();
        req.pid = m_ses.get_peer_id();
        req.downloaded = m_stat.total_payload_download() - m_total_failed_bytes;
        req.uploaded = m_stat.total_payload_upload();
        req.corrupt = m_total_failed_bytes;
        req.left = bytes_left();
        if (req.left == -1) req.left = 16*1024;
#ifdef TORRENT_USE_OPENSSL
        // if this torrent contains an SSL certificate, make sure
        // any SSL tracker presents a certificate signed by it
        req.ssl_ctx = m_ssl_ctx.get();
#endif

        // exclude redundant bytes if we should
        if (!settings().report_true_downloaded)
            req.downloaded -= m_total_redundant_bytes;
        if (req.downloaded < 0) req.downloaded = 0;

        req.event = e;
        error_code ec;
        if (!m_ses.m_settings.anonymous_mode)
        {
            tcp::endpoint ep;
            ep = m_ses.get_ipv6_interface();
            if (ep != tcp::endpoint()) req.ipv6 = ep.address().to_string(ec);
            ep = m_ses.get_ipv4_interface();
            if (ep != tcp::endpoint()) req.ipv4 = ep.address().to_string(ec);
        }

        // if we are aborting. we don't want any new peers
        req.num_want = (req.event == tracker_request::stopped)
            ?0:settings().num_want;

        // SSL torrents use their own listen socket
#ifdef TORRENT_USE_OPENSSL
        // TODO: this pattern is repeated in a few places. Factor this into
        // a function and generalize the concept of a torrent having a
        // dedicated listen port
        if (is_ssl_torrent()) req.listen_port = m_ssl_acceptor->external_port;
        else
#endif
        req.listen_port = m_ses.listen_port();
        req.key = m_ses.m_key;

        ptime now = time_now_hires();

        // the tier is kept as INT_MAX until we find the first
        // tracker that works, then it's set to that tracker's
        // tier.
        int tier = INT_MAX;

        // have we sent an announce in this tier yet?
        bool sent_announce = false;

        for (int i = 0; i < int(m_trackers.size()); ++i)
        {
            announce_entry& ae = m_trackers[i];
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
            char msg[1000];
            snprintf(msg, sizeof(msg), "*** announce with tracker: considering \"%s\" "
                "[ announce_to_all_tiers: %d announce_to_all_trackers: %d"
                " i->tier: %d tier: %d "
                " is_working: %d fails: %d fail_limit: %d updating: %d"
                " can_announce: %d sent_announce: %d ]"
                , ae.url.c_str(), settings().announce_to_all_tiers
                , settings().announce_to_all_trackers
                , ae.tier, tier, ae.is_working(), ae.fails, ae.fail_limit
                , ae.updating, ae.can_announce(now, is_seed()), sent_announce);
            debug_log(msg);
#endif
            // if trackerid is not specified for tracker use default one, probably set explicitly
            req.trackerid = ae.trackerid.empty() ? m_trackerid : ae.trackerid;
            if (settings().announce_to_all_tiers
                && !settings().announce_to_all_trackers
                && sent_announce
                && ae.tier <= tier
                && tier != INT_MAX)
                continue;

            if (ae.tier > tier && sent_announce && !settings().announce_to_all_tiers) break;
            if (ae.is_working()) { tier = ae.tier; sent_announce = false; }
            if (!ae.can_announce(now, is_seed()))
            {
                // this counts
                if (ae.is_working()) sent_announce = true;
                continue;
            }

            req.url = ae.url;
            req.event = e;
            if (req.event == tracker_request::none)
            {
                if (!ae.start_sent) req.event = tracker_request::started;
                else if (!ae.complete_sent && is_seed()) req.event = tracker_request::completed;
            }

            if (!is_any(bind_interface)) req.bind_ip = bind_interface;
            else req.bind_ip = m_ses.m_listen_interface.address();

            if (settings().anonymous_mode)
            {
                // in anonymous_mode we don't talk directly to trackers
                // only if there is a proxy
                std::string protocol = req.url.substr(0, req.url.find(':'));
                int proxy_type = m_ses.m_proxy.type;

                if ((protocol == "http" || protocol == "https")
                    && proxy_type == proxy_settings::none)
                {
                    ae.next_announce = now + minutes(10);
                    if (m_ses.m_alerts.should_post<anonymous_mode_alert>())
                    {
                        m_ses.m_alerts.post_alert(
                            anonymous_mode_alert(get_handle()
                                , anonymous_mode_alert::tracker_not_anonymous, req.url));
                    }
                    continue;
                }

                if (protocol == "udp"
                    || (proxy_type != proxy_settings::socks5
                    && proxy_type != proxy_settings::socks5_pw
                    && proxy_type != proxy_settings::i2p_proxy))
                {
                    ae.next_announce = now + minutes(10);
                    if (m_ses.m_alerts.should_post<anonymous_mode_alert>())
                    {
                        m_ses.m_alerts.post_alert(
                            anonymous_mode_alert(get_handle()
                                , anonymous_mode_alert::tracker_not_anonymous, req.url));
                    }
                    continue;
                }
            }
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
            (*m_ses.m_logger) << time_now_string() << " ==> TACKER REQUEST " << req.url
                << " event=" << (req.event==tracker_request::stopped?"stopped"
                    :req.event==tracker_request::started?"started":"")
                << " abort=" << m_abort << "\n";
            if (m_abort)
            {
                boost::shared_ptr<aux::tracker_logger> tl(new aux::tracker_logger(m_ses));
                m_ses.m_tracker_manager.queue_request(m_ses.m_io_service, m_ses.m_half_open, req
                    , tracker_login(), tl);
            }
            else
#endif
            m_ses.m_tracker_manager.queue_request(m_ses.m_io_service, m_ses.m_half_open, req
                , tracker_login() , shared_from_this());
            ae.updating = true;
            ae.next_announce = now + seconds(20);
            ae.min_announce = now + seconds(10);

            if (m_ses.m_alerts.should_post<tracker_announce_alert>())
            {
                m_ses.m_alerts.post_alert(
                    tracker_announce_alert(get_handle(), req.url, req.event));
            }

            sent_announce = true;
            if (ae.is_working()
                && !settings().announce_to_all_trackers
                && !settings().announce_to_all_tiers)
                break;
        }
        update_tracker_timer(now);
    }

    void torrent::scrape_tracker()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        m_last_scrape = 0;

        if (m_trackers.empty()) return;

        int i = m_last_working_tracker;
        if (i == -1) i = 0;

        tracker_request req;
        req.apply_ip_filter = m_apply_ip_filter && m_ses.m_settings.apply_ip_filter_to_trackers;
        req.info_hash = m_torrent_file->info_hash();
        req.kind = tracker_request::scrape_request;
        req.url = m_trackers[i].url;
        req.bind_ip = m_ses.m_listen_interface.address();
        m_ses.m_tracker_manager.queue_request(m_ses.m_io_service, m_ses.m_half_open, req
            , tracker_login(), shared_from_this());
    }

    void torrent::tracker_warning(tracker_request const& req, std::string const& msg)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

        if (m_ses.m_alerts.should_post<tracker_warning_alert>())
            m_ses.m_alerts.post_alert(tracker_warning_alert(get_handle(), req.url, msg));
    }

     void torrent::tracker_scrape_response(tracker_request const& req
         , int complete, int incomplete, int downloaded, int downloaders)
     {
        TORRENT_ASSERT(m_ses.is_network_thread());

         INVARIANT_CHECK;
        TORRENT_ASSERT(req.kind == tracker_request::scrape_request);

         if (complete >= 0) m_complete = complete;
         if (incomplete >= 0) m_incomplete = incomplete;
         if (downloaders >= 0) m_downloaders = downloaders;

         if (m_ses.m_alerts.should_post<scrape_reply_alert>())
         {
             m_ses.m_alerts.post_alert(scrape_reply_alert(
                 get_handle(), m_incomplete, m_complete, req.url));
         }
     }

    void torrent::tracker_response(
        tracker_request const& r
        , address const& tracker_ip // this is the IP we connected to
        , std::list<address> const& tracker_ips // these are all the IPs it resolved to
        , std::vector<peer_entry>& peer_list
        , int interval
        , int min_interval
        , int complete
        , int incomplete
        , address const& external_ip
        , const std::string& trackerid)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;
        TORRENT_ASSERT(r.kind == tracker_request::announce_request);

        TORRENT_ASSERT(!tracker_ips.empty());
        if (external_ip != address())
            m_ses.set_external_address(external_ip, aux::session_impl::source_tracker
                , *tracker_ips.begin());

        ptime now = time_now();

        if (interval < settings().min_announce_interval)
            interval = settings().min_announce_interval;

        announce_entry* ae = find_tracker(r);
        if (ae)
        {
            if (!ae->start_sent && r.event == tracker_request::started)
                ae->start_sent = true;
            if (!ae->complete_sent && r.event == tracker_request::completed)
                ae->complete_sent = true;
            ae->verified = true;
            ae->updating = false;
            ae->fails = 0;
            ae->next_announce = now + seconds(interval);
            ae->min_announce = now + seconds(min_interval);
            int tracker_index = ae - &m_trackers[0];
            m_last_working_tracker = prioritize_tracker(tracker_index);

            if ((!trackerid.empty()) && (ae->trackerid != trackerid))
            {
                ae->trackerid = trackerid;
                if (m_ses.m_alerts.should_post<trackerid_alert>())
                m_ses.m_alerts.post_alert(trackerid_alert(get_handle(), r.url, trackerid));
            }
        }
        update_tracker_timer(now);

        if (complete >= 0) m_complete = complete;
        if (incomplete >= 0) m_incomplete = incomplete;
        if (complete >= 0 && incomplete >= 0)
            m_last_scrape = 0;

#if (defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING) && TORRENT_USE_IOSTREAM
        std::stringstream s;
        s << "TRACKER RESPONSE:\n"
            "interval: " << interval << "\n"
            "peers:\n";
        for (std::vector<peer_entry>::const_iterator i = peer_list.begin();
            i != peer_list.end(); ++i)
        {
            s << "  " << std::setfill(' ') << std::setw(16) << i->ip
                << " " << std::setw(5) << std::dec << i->port << "  ";
            if (!i->pid.is_all_zeros()) s << " " << i->pid << " " << identify_client(i->pid);
            s << "\n";
        }
        s << "external ip: " << external_ip << "\n";
        s << "tracker ips: ";
        std::copy(tracker_ips.begin(), tracker_ips.end(), std::ostream_iterator<address>(s, " "));
        s << "\n";
        s << "we connected to: " << tracker_ip << "\n";
        debug_log(s.str());
#endif
        // for each of the peers we got from the tracker
        for (std::vector<peer_entry>::iterator i = peer_list.begin();
            i != peer_list.end(); ++i)
        {
            // don't make connections to ourself
            if (i->pid == m_ses.get_peer_id())
                continue;

            error_code ec;
            tcp::endpoint a(address::from_string(i->ip, ec), i->port);

            if (ec)
            {
                // assume this is because we got a hostname instead of
                // an ip address from the tracker

#if TORRENT_USE_I2P
                char const* top_domain = strrchr(i->ip.c_str(), '.');
                if (top_domain && strcmp(top_domain, ".i2p") == 0 && m_ses.m_i2p_conn.is_open())
                {
                    // this is an i2p name, we need to use the sam connection
                    // to do the name lookup
                    /*
                    m_ses.m_i2p_conn.async_name_lookup(i->ip.c_str()
                        , boost::bind(&torrent::on_i2p_resolve
                        , shared_from_this(), _1, _2));
                    */
                    // it seems like you're not supposed to do a name lookup
                    // on the peers returned from the tracker, but just strip
                    // the .i2p and use it as a destination
                    i->ip.resize(i->ip.size() - 4);
                    m_policy.add_i2p_peer(i->ip.c_str(), peer_info::tracker, 0);
                }
                else
#endif
                {
#if defined TORRENT_ASIO_DEBUGGING
                    add_outstanding_async("torrent::on_peer_name_lookup");
#endif
                    tcp::resolver::query q(i->ip, to_string(i->port).elems);
                    m_ses.m_host_resolver.async_resolve(q,
                        boost::bind(&torrent::on_peer_name_lookup, shared_from_this(), _1, _2, i->pid));
                }
            }
            else
            {
                // ignore local addresses from the tracker (unless the tracker is local too)
                if (is_local(a.address()) && !is_local(tracker_ip)) continue;
                m_policy.add_peer(a, i->pid, peer_info::tracker, 0);
            }
        }

        if (m_ses.m_alerts.should_post<tracker_reply_alert>())
        {
            m_ses.m_alerts.post_alert(tracker_reply_alert(
                get_handle(), peer_list.size(), r.url));
        }
        m_got_tracker_response = true;

        // we're listening on an interface type that was not used
        // when talking to the tracker. If there is a matching interface
        // type in the tracker IP list, make another tracker request
        // using that interface
        // in order to avoid triggering this case over and over, don't
        // do it if the bind IP for the tracker request that just completed
        // matches one of the listen interfaces, since that means this
        // announce was the second one
        // don't connect twice just to tell it we're stopping

        if (((!is_any(m_ses.m_ipv6_interface.address()) && tracker_ip.is_v4())
            || (!is_any(m_ses.m_ipv4_interface.address()) && tracker_ip.is_v6()))
            && r.bind_ip != m_ses.m_ipv4_interface.address()
            && r.bind_ip != m_ses.m_ipv6_interface.address()
            && r.event != tracker_request::stopped)
        {
            std::list<address>::const_iterator i = std::find_if(tracker_ips.begin()
                , tracker_ips.end(), boost::bind(&address::is_v4, _1) != tracker_ip.is_v4());
            if (i != tracker_ips.end())
            {
                // the tracker did resolve to a different type of address, so announce
                // to that as well

                // tell the tracker to bind to the opposite protocol type
                address bind_interface = tracker_ip.is_v4()
                    ?m_ses.m_ipv6_interface.address()
                    :m_ses.m_ipv4_interface.address();
                announce_with_tracker(r.event, bind_interface);
#if (defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING) && TORRENT_USE_IOSTREAM
                debug_log("announce again using " + print_address(bind_interface)
                    + " as the bind interface");
#endif
            }
        }

        if (m_need_connect_boost)
        {
            m_need_connect_boost = false;
            // this is the first tracker response for this torrent
            // instead of waiting one second for session_impl::on_tick()
            // to be called, connect to a few peers immediately
            int conns = (std::min)((std::min)((std::min)(m_ses.m_settings.torrent_connect_boost
                , m_ses.m_settings.connections_limit - m_ses.num_connections())
                , m_ses.m_half_open.free_slots())
                , m_ses.m_boost_connections - m_ses.m_settings.connection_speed);

            while (want_more_peers() && conns > 0)
            {
                if (!m_policy.connect_one_peer(m_ses.session_time())) break;
                // increase m_ses.m_boost_connections for each connection
                // attempt. This will be deducted from the connect speed
                // the next time session_impl::on_tick() is triggered
                --conns;
                ++m_ses.m_boost_connections;
            }
        }
    }

    ptime torrent::next_announce() const
    {
        return m_waiting_tracker?m_tracker_timer.expires_at():min_time();
    }

    void torrent::force_tracker_request()
    {
        force_tracker_request(time_now_hires());
    }

    void torrent::force_tracker_request(ptime t)
    {
        if (is_paused()) return;
        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
            i->next_announce = (std::max)(t, i->min_announce) + seconds(1);
        update_tracker_timer(time_now_hires());
    }

    void torrent::set_tracker_login(
        std::string const& name
        , std::string const& pw)
    {
        m_username = name;
        m_password = pw;
    }

#if TORRENT_USE_I2P
    void torrent::on_i2p_resolve(error_code const& ec, char const* dest)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

#if defined TORRENT_LOGGING
        if (ec)
            *m_ses.m_logger << time_now_string() << " on_i2p_resolve: " << ec.message() << "\n";
#endif
        if (ec || m_ses.is_aborted()) return;

        m_policy.add_i2p_peer(dest, peer_info::tracker, 0);
    }
#endif

    void torrent::on_peer_name_lookup(error_code const& e, tcp::resolver::iterator host
        , peer_id pid)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

#if defined TORRENT_ASIO_DEBUGGING
        complete_async("torrent::on_peer_name_lookup");
#endif

#if defined TORRENT_LOGGING
        if (e)
            *m_ses.m_logger << time_now_string() << " on_peer_name_lookup: " << e.message() << "\n";
#endif
        if (e || host == tcp::resolver::iterator() ||
            m_ses.is_aborted()) return;

        if (m_apply_ip_filter
            && m_ses.m_ip_filter.access(host->endpoint().address()) & ip_filter::blocked)
        {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
            error_code ec;
            debug_log("blocked ip from tracker: " + host->endpoint().address().to_string(ec));
#endif
            if (m_ses.m_alerts.should_post<peer_blocked_alert>())
                m_ses.m_alerts.post_alert(peer_blocked_alert(get_handle(), host->endpoint().address()));
            return;
        }

        m_policy.add_peer(*host, pid, peer_info::tracker, 0);
    }

    size_type torrent::bytes_left() const
    {
        // if we don't have the metadata yet, we
        // cannot tell how big the torrent is.
        if (!valid_metadata()) return -1;
        return m_torrent_file->total_size()
            - quantized_bytes_done();
    }

    size_type torrent::quantized_bytes_done() const
    {
//		INVARIANT_CHECK;

        if (!valid_metadata()) return 0;

        if (m_torrent_file->num_pieces() == 0)
            return 0;

        if (is_seed()) return m_torrent_file->total_size();

        const int last_piece = m_torrent_file->num_pieces() - 1;

        size_type total_done
            = size_type(num_have()) * m_torrent_file->piece_length();

        // if we have the last piece, we have to correct
        // the amount we have, since the first calculation
        // assumed all pieces were of equal size
        if (m_picker->have_piece(last_piece))
        {
            int corr = m_torrent_file->piece_size(last_piece)
                - m_torrent_file->piece_length();
            total_done += corr;
        }
        return total_done;
    }

    // returns the number of bytes we are interested
    // in for the given block. This returns block_size()
    // for all blocks except the last one (if it's smaller
    // than block_size()) and blocks that overlap a padding
    // file
    int torrent::block_bytes_wanted(piece_block const& p) const
    {
        file_storage const& fs = m_torrent_file->files();
        int piece_size = m_torrent_file->piece_size(p.piece_index);
        int offset = p.block_index * block_size();
        if (m_padding == 0) return (std::min)(piece_size - offset, int(block_size()));

        std::vector<file_slice> files = fs.map_block(
            p.piece_index, offset, (std::min)(piece_size - offset, int(block_size())));
        int ret = 0;
        for (std::vector<file_slice>::iterator i = files.begin()
            , end(files.end()); i != end; ++i)
        {
            file_entry const& fe = fs.at(i->file_index);
            if (fe.pad_file) continue;
            ret += i->size;
        }
        TORRENT_ASSERT(ret <= (std::min)(piece_size - offset, int(block_size())));
        return ret;
    }

    // fills in total_wanted, total_wanted_done and total_done
    void torrent::bytes_done(torrent_status& st, bool accurate) const
    {
        INVARIANT_CHECK;

        st.total_done = 0;
        st.total_wanted_done = 0;
        st.total_wanted = m_torrent_file->total_size();

        TORRENT_ASSERT(st.total_wanted >= m_padding);
        TORRENT_ASSERT(st.total_wanted >= 0);

        if (!valid_metadata() || m_torrent_file->num_pieces() == 0)
            return;

        TORRENT_ASSERT(st.total_wanted >= m_torrent_file->piece_length()
            * (m_torrent_file->num_pieces() - 1));

        const int last_piece = m_torrent_file->num_pieces() - 1;
        const int piece_size = m_torrent_file->piece_length();

        if (is_seed())
        {
            st.total_done = m_torrent_file->total_size() - m_padding;
            st.total_wanted_done = st.total_done;
            st.total_wanted = st.total_done;
            return;
        }

        TORRENT_ASSERT(num_have() >= m_picker->num_have_filtered());
        st.total_wanted_done = size_type(num_have() - m_picker->num_have_filtered())
            * piece_size;
        TORRENT_ASSERT(st.total_wanted_done >= 0);

        st.total_done = size_type(num_have()) * piece_size;
        TORRENT_ASSERT(num_have() < m_torrent_file->num_pieces());

        int num_filtered_pieces = m_picker->num_filtered()
            + m_picker->num_have_filtered();
        int last_piece_index = m_torrent_file->num_pieces() - 1;
        if (m_picker->piece_priority(last_piece_index) == 0)
        {
            st.total_wanted -= m_torrent_file->piece_size(last_piece_index);
            --num_filtered_pieces;
        }
        st.total_wanted -= size_type(num_filtered_pieces) * piece_size;

        // if we have the last piece, we have to correct
        // the amount we have, since the first calculation
        // assumed all pieces were of equal size
        if (m_picker->have_piece(last_piece))
        {
            TORRENT_ASSERT(st.total_done >= piece_size);
            int corr = m_torrent_file->piece_size(last_piece)
                - piece_size;
            TORRENT_ASSERT(corr <= 0);
            TORRENT_ASSERT(corr > -piece_size);
            st.total_done += corr;
            if (m_picker->piece_priority(last_piece) != 0)
            {
                TORRENT_ASSERT(st.total_wanted_done >= piece_size);
                st.total_wanted_done += corr;
            }
        }
        TORRENT_ASSERT(st.total_wanted >= st.total_wanted_done);

        // subtract padding files
        if (m_padding > 0)
        {
            file_storage const& files = m_torrent_file->files();
            int fileno = 0;
            for (file_storage::iterator i = files.begin()
                    , end(files.end()); i != end; ++i, ++fileno)
            {
                if (!i->pad_file) continue;
                peer_request p = files.map_file(fileno, 0, i->size);
                for (int j = p.piece; p.length > 0; ++j, p.length -= piece_size)
                {
                    int deduction = (std::min)(p.length, piece_size);
                    bool done = m_picker->have_piece(j);
                    bool wanted = m_picker->piece_priority(j) > 0;
                    if (done) st.total_done -= deduction;
                    if (wanted) st.total_wanted -= deduction;
                    if (wanted && done) st.total_wanted_done -= deduction;
                }
            }
        }

        TORRENT_ASSERT(st.total_done <= m_torrent_file->total_size() - m_padding);
        TORRENT_ASSERT(st.total_wanted_done <= m_torrent_file->total_size() - m_padding);
        TORRENT_ASSERT(st.total_wanted_done >= 0);
        TORRENT_ASSERT(st.total_done >= st.total_wanted_done);

        // this is expensive, we might not want to do it all the time
        if (!accurate) return;

        const std::vector<piece_picker::downloading_piece>& dl_queue
            = m_picker->get_download_queue();

        const int blocks_per_piece = (piece_size + block_size() - 1) / block_size();

        // look at all unfinished pieces and add the completed
        // blocks to our 'done' counter
        for (std::vector<piece_picker::downloading_piece>::const_iterator i =
            dl_queue.begin(); i != dl_queue.end(); ++i)
        {
            int corr = 0;
            int index = i->index;
            // completed pieces are already accounted for
            if (m_picker->have_piece(index)) continue;
            TORRENT_ASSERT(i->finished <= m_picker->blocks_in_piece(index));

#ifdef TORRENT_DEBUG
            for (std::vector<piece_picker::downloading_piece>::const_iterator j = boost::next(i);
                j != dl_queue.end(); ++j)
            {
                TORRENT_ASSERT(j->index != index);
            }
#endif

            for (int j = 0; j < blocks_per_piece; ++j)
            {
#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
                TORRENT_ASSERT(m_picker->is_finished(piece_block(index, j))
                    == (i->info[j].state == piece_picker::block_info::state_finished));
#endif
                if (i->info[j].state == piece_picker::block_info::state_finished)
                {
                    corr += block_bytes_wanted(piece_block(index, j));
                }
                TORRENT_ASSERT(corr >= 0);
                TORRENT_ASSERT(index != last_piece || j < m_picker->blocks_in_last_piece()
                    || i->info[j].state != piece_picker::block_info::state_finished);
            }

            st.total_done += corr;
            if (m_picker->piece_priority(index) > 0)
                st.total_wanted_done += corr;
        }

        TORRENT_ASSERT(st.total_wanted <= m_torrent_file->total_size() - m_padding);
        TORRENT_ASSERT(st.total_done <= m_torrent_file->total_size() - m_padding);
        TORRENT_ASSERT(st.total_wanted_done <= m_torrent_file->total_size() - m_padding);
        TORRENT_ASSERT(st.total_wanted_done >= 0);
        TORRENT_ASSERT(st.total_done >= st.total_wanted_done);

        std::map<piece_block, int> downloading_piece;
        for (const_peer_iterator i = begin(); i != end(); ++i)
        {
            peer_connection* pc = *i;
            boost::optional<piece_block_progress> p
                = pc->downloading_piece_progress();
            if (!p) continue;

            if (m_picker->have_piece(p->piece_index))
                continue;

            piece_block block(p->piece_index, p->block_index);
            if (m_picker->is_finished(block))
                continue;

            std::map<piece_block, int>::iterator dp
                = downloading_piece.find(block);
            if (dp != downloading_piece.end())
            {
                if (dp->second < p->bytes_downloaded)
                    dp->second = p->bytes_downloaded;
            }
            else
            {
                downloading_piece[block] = p->bytes_downloaded;
            }
#ifdef TORRENT_DEBUG
            TORRENT_ASSERT(p->bytes_downloaded <= p->full_block_bytes);
            TORRENT_ASSERT(p->full_block_bytes == to_req(piece_block(
                p->piece_index, p->block_index)).length);
#endif
        }
        for (std::map<piece_block, int>::iterator i = downloading_piece.begin();
            i != downloading_piece.end(); ++i)
        {
            int done = (std::min)(block_bytes_wanted(i->first), i->second);
            st.total_done += done;
            if (m_picker->piece_priority(i->first.piece_index) != 0)
                st.total_wanted_done += done;
        }

        TORRENT_ASSERT(st.total_done <= m_torrent_file->total_size() - m_padding);
        TORRENT_ASSERT(st.total_wanted_done <= m_torrent_file->total_size() - m_padding);

#ifdef TORRENT_DEBUG

        if (st.total_done >= m_torrent_file->total_size())
        {
            // Thist happens when a piece has been downloaded completely
            // but not yet verified against the hash
            fprintf(stderr, "num_have: %d\nunfinished:\n", num_have());
            for (std::vector<piece_picker::downloading_piece>::const_iterator i =
                dl_queue.begin(); i != dl_queue.end(); ++i)
            {
                fprintf(stderr, "  %d ", i->index);
                for (int j = 0; j < blocks_per_piece; ++j)
                {
                    char const* state = i->info[j].state == piece_picker::block_info::state_finished ? "1" : "0";
                    fputs(state, stderr);
                }
                fputs("\n", stderr);
            }

            fputs("downloading pieces:\n", stderr);

            for (std::map<piece_block, int>::iterator i = downloading_piece.begin();
                i != downloading_piece.end(); ++i)
            {
                fprintf(stderr, "   %d:%d  %d\n", int(i->first.piece_index), int(i->first.block_index), i->second);
            }

        }

        TORRENT_ASSERT(st.total_done <= m_torrent_file->total_size());
        TORRENT_ASSERT(st.total_wanted_done <= m_torrent_file->total_size());

#endif

        TORRENT_ASSERT(st.total_done >= st.total_wanted_done);
    }

    // passed_hash_check
    // 0: success, piece passed check
    // -1: disk failure
    // -2: piece failed check
    void torrent::piece_finished(int index, int passed_hash_check)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
        (*m_ses.m_logger) << time_now_string() << " *** PIECE_FINISHED [ p: "
            << index << " chk: " << ((passed_hash_check == 0)
                ?"passed":passed_hash_check == -1
                ?"disk failed":"failed") << " size: "
            << m_torrent_file->piece_size(index) << " ]\n";
#endif

        TORRENT_ASSERT(valid_metadata());

        TORRENT_ASSERT(!m_picker->have_piece(index));

        // even though the piece passed the hash-check
        // it might still have failed being written to disk
        // if so, piece_picker::write_failed() has been
        // called, and the piece is no longer finished.
        // in this case, we have to ignore the fact that
        // it passed the check
        if (!m_picker->is_piece_finished(index)) return;

        if (passed_hash_check == 0)
        {
            // the following call may cause picker to become invalid
            // in case we just became a seed
            piece_passed(index);
            // if we're in seed mode, we just acquired this piece
            // mark it as verified
            if (m_seed_mode) verified(index);
        }
        else if (passed_hash_check == -2)
        {
            // piece_failed() will restore the piece
            piece_failed(index);
        }
        else
        {
            TORRENT_ASSERT(passed_hash_check == -1);
            m_picker->restore_piece(index);
            restore_piece_state(index);
        }
    }

    void torrent::update_sparse_piece_prio(int i, int start, int end)
    {
        TORRENT_ASSERT(m_picker);
        if (m_picker->have_piece(i) || m_picker->piece_priority(i) == 0)
            return;
        bool have_before = i == 0 || m_picker->have_piece(i - 1);
        bool have_after = i == end - 1 || m_picker->have_piece(i + 1);
        if (have_after && have_before)
            m_picker->set_piece_priority(i, 7);
        else if (have_after || have_before)
            m_picker->set_piece_priority(i, 6);
    }

    void torrent::we_have(int index)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        // update m_file_progress
        TORRENT_ASSERT(m_picker);
        TORRENT_ASSERT(!have_piece(index));
        TORRENT_ASSERT(!m_picker->have_piece(index));

        const int piece_size = m_torrent_file->piece_length();
        size_type off = size_type(index) * piece_size;
        file_storage::iterator f = m_torrent_file->files().file_at_offset(off);
        int size = m_torrent_file->piece_size(index);
        int file_index = f - m_torrent_file->files().begin();
        for (; size > 0; ++f, ++file_index)
        {
            size_type file_offset = off - f->offset;
            TORRENT_ASSERT(f != m_torrent_file->files().end());
            TORRENT_ASSERT(file_offset <= f->size);
            int add = (std::min)(f->size - file_offset, (size_type)size);
            m_file_progress[file_index] += add;

            TORRENT_ASSERT(m_file_progress[file_index]
                <= m_torrent_file->files().at(file_index).size);

            if (m_file_progress[file_index] >= m_torrent_file->files().at(file_index).size)
            {
                if (!m_torrent_file->files().at(file_index).pad_file)
                {
                    if (m_owning_storage.get())
                        m_storage->async_finalize_file(file_index);

                    if (m_ses.m_alerts.should_post<piece_finished_alert>())
                    {
                        // this file just completed, post alert
                        m_ses.m_alerts.post_alert(file_completed_alert(get_handle()
                            , file_index));
                    }
                }
            }
            size -= add;
            off += add;
            TORRENT_ASSERT(size >= 0);
        }

        m_picker->we_have(index);
    }

    void torrent::piece_passed(int index)
    {
//		INVARIANT_CHECK;
        TORRENT_ASSERT(m_ses.is_network_thread());

        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < m_torrent_file->num_pieces());
#ifdef TORRENT_DEBUG
        // make sure all blocks were successfully written before we
        // declare the piece as "we have".
        piece_picker::downloading_piece dp;
        m_picker->piece_info(index, dp);
        int blocks_in_piece = m_picker->blocks_in_piece(index);
        TORRENT_ASSERT(dp.finished == blocks_in_piece);
        TORRENT_ASSERT(dp.writing == 0);
        TORRENT_ASSERT(dp.requested == 0);
        TORRENT_ASSERT(dp.index == index);
#endif

        if (m_ses.m_alerts.should_post<piece_finished_alert>())
        {
            m_ses.m_alerts.post_alert(piece_finished_alert(get_handle()
                , index));
        }

        m_need_save_resume_data = true;

        remove_time_critical_piece(index, true);

        bool was_finished = m_picker->num_filtered() + num_have()
            == torrent_file().num_pieces();

        std::vector<void*> downloaders;
        m_picker->get_downloaders(downloaders, index);

        // increase the trust point of all peers that sent
        // parts of this piece.
        std::set<void*> peers;
        std::copy(downloaders.begin(), downloaders.end(), std::inserter(peers, peers.begin()));

        we_have(index);

        for (peer_iterator i = m_connections.begin(); i != m_connections.end();)
        {
            intrusive_ptr<peer_connection> p = *i;
            ++i;
            p->announce_piece(index);
        }

        for (std::set<void*>::iterator i = peers.begin()
            , end(peers.end()); i != end; ++i)
        {
            policy::peer* p = static_cast<policy::peer*>(*i);
            if (p == 0) continue;
            p->on_parole = false;
            int trust_points = p->trust_points;
            ++trust_points;
            if (trust_points > 8) trust_points = 8;
            p->trust_points = trust_points;
            if (p->connection) p->connection->received_valid_data(index);
        }

        if (settings().max_sparse_regions > 0
            && m_picker->sparse_regions() > settings().max_sparse_regions)
        {
            // we have too many sparse regions. Prioritize pieces
            // that won't introduce new sparse regions
            // prioritize pieces that will reduce the number of sparse
            // regions even higher
            int start = m_picker->cursor();
            int end = m_picker->reverse_cursor();
            if (index > start) update_sparse_piece_prio(index - 1, start, end);
            if (index < end - 1) update_sparse_piece_prio(index + 1, start, end);
        }

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                (*i)->on_piece_pass(index);
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

        // since this piece just passed, we might have
        // become uninterested in some peers where this
        // was the last piece we were interested in
        for (peer_iterator i = m_connections.begin();
            i != m_connections.end();)
        {
            peer_connection* p = *i;
            // update_interest may disconnect the peer and
            // invalidate the iterator
            ++i;
            // if we're not interested already, no need to check
            if (!p->is_interesting()) continue;
            // if the peer doesn't have the piece we just got, it
            // wouldn't affect our interest
            if (!p->has_piece(index)) continue;
            p->update_interest();
        }

        if (!was_finished && is_finished())
        {
            // torrent finished
            // i.e. all the pieces we're interested in have
            // been downloaded. Release the files (they will open
            // in read only mode if needed)
            finished();
            // if we just became a seed, picker is now invalid, since it
            // is deallocated by the torrent once it starts seeding
        }

        m_last_download = 0;

        if (m_share_mode)
            recalc_share_mode();
    }

    void torrent::piece_failed(int index)
    {
        // if the last piece fails the peer connection will still
        // think that it has received all of it until this function
        // resets the download queue. So, we cannot do the
        // invariant check here since it assumes:
        // (total_done == m_torrent_file->total_size()) => is_seed()
        INVARIANT_CHECK;
        TORRENT_ASSERT(m_ses.is_network_thread());

        TORRENT_ASSERT(m_storage);
        TORRENT_ASSERT(m_storage->refcount() > 0);
        TORRENT_ASSERT(m_picker.get());
        TORRENT_ASSERT(index >= 0);
          TORRENT_ASSERT(index < m_torrent_file->num_pieces());

        if (m_ses.m_alerts.should_post<hash_failed_alert>())
            m_ses.m_alerts.post_alert(hash_failed_alert(get_handle(), index));

        // increase the total amount of failed bytes
        add_failed_bytes(m_torrent_file->piece_size(index));

        std::vector<void*> downloaders;
        m_picker->get_downloaders(downloaders, index);

        // decrease the trust point of all peers that sent
        // parts of this piece.
        // first, build a set of all peers that participated
        std::set<void*> peers;
        std::copy(downloaders.begin(), downloaders.end(), std::inserter(peers, peers.begin()));

#ifdef TORRENT_DEBUG
        for (std::vector<void*>::iterator i = downloaders.begin()
            , end(downloaders.end()); i != end; ++i)
        {
            policy::peer* p = (policy::peer*)*i;
            if (p && p->connection)
            {
                p->connection->piece_failed = true;
            }
        }
#endif

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                (*i)->on_piece_failed(index);
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

        for (std::set<void*>::iterator i = peers.begin()
            , end(peers.end()); i != end; ++i)
        {
            policy::peer* p = static_cast<policy::peer*>(*i);
            if (p == 0) continue;
            if (p->connection) p->connection->received_invalid_data(index);

            // either, we have received too many failed hashes
            // or this was the only peer that sent us this piece.
            if (p->trust_points <= -7
                || peers.size() == 1)
            {
                // we don't trust this peer anymore
                // ban it.
                if (m_ses.m_alerts.should_post<peer_ban_alert>())
                {
                    peer_id pid(0);
                    if (p->connection) pid = p->connection->pid();
                    m_ses.m_alerts.post_alert(peer_ban_alert(
                        get_handle(), p->ip(), pid));
                }

                // mark the peer as banned
                m_policy.ban_peer(p);
#ifdef TORRENT_STATS
                ++m_ses.m_banned_for_hash_failure;
#endif

                if (p->connection)
                {
#ifdef TORRENT_LOGGING
                    (*m_ses.m_logger) << time_now_string() << " *** BANNING PEER [ " << p->ip()
                        << " ] 'too many corrupt pieces'\n";
#endif
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
                    (*p->connection->m_logger) << "*** BANNING PEER [ " << p->ip()
                        << " ] 'too many corrupt pieces'\n";
#endif
                    p->connection->disconnect(errors::too_many_corrupt_pieces);
                }
            }
        }

        // we have to let the piece_picker know that
        // this piece failed the check as it can restore it
        // and mark it as being interesting for download
        m_picker->restore_piece(index);

        // we might still have outstanding requests to this
        // piece that hasn't been received yet. If this is the
        // case, we need to re-open the piece and mark any
        // blocks we're still waiting for as requested
        restore_piece_state(index);

        TORRENT_ASSERT(m_storage);

        TORRENT_ASSERT(m_picker->have_piece(index) == false);

#ifdef TORRENT_DEBUG
        for (std::vector<void*>::iterator i = downloaders.begin()
            , end(downloaders.end()); i != end; ++i)
        {
            policy::peer* p = (policy::peer*)*i;
            if (p && p->connection)
            {
                p->connection->piece_failed = false;
            }
        }
#endif
    }

    void torrent::restore_piece_state(int index)
    {
        TORRENT_ASSERT(has_picker());
        for (peer_iterator i = m_connections.begin();
            i != m_connections.end(); ++i)
        {
            peer_connection* p = *i;
            std::vector<pending_block> const& dq = p->download_queue();
            std::vector<pending_block> const& rq = p->request_queue();
            for (std::vector<pending_block>::const_iterator k = dq.begin()
                , end(dq.end()); k != end; ++k)
            {
                if (k->timed_out || k->not_wanted) continue;
                if (int(k->block.piece_index) != index) continue;
                m_picker->mark_as_downloading(k->block, p->peer_info_struct()
                    , (piece_picker::piece_state_t)p->peer_speed());
            }
            for (std::vector<pending_block>::const_iterator k = rq.begin()
                , end(rq.end()); k != end; ++k)
            {
                if (int(k->block.piece_index) != index) continue;
                m_picker->mark_as_downloading(k->block, p->peer_info_struct()
                    , (piece_picker::piece_state_t)p->peer_speed());
            }
        }
    }

    void torrent::abort()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (m_abort) return;

#ifdef TORRENT_USE_OPENSSL
        if (m_torrent_file->is_valid() && m_torrent_file->encryption_key().size() == 32 && m_in_encrypted_list)
        {
            m_ses.m_encrypted_torrents.erase(shared_from_this());
            m_in_encrypted_list = false;
        }

        if (m_ssl_acceptor && m_ssl_acceptor->sock)
        {
            error_code ec;
            m_ssl_acceptor->sock->close(ec);
        }
#endif

        m_abort = true;
        // if the torrent is paused, it doesn't need
        // to announce with even=stopped again.
        if (!is_paused())
        {
            stop_announcing();
        }

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING || defined TORRENT_LOGGING
        log_to_all_peers("ABORTING TORRENT");
#endif

        // disconnect all peers and close all
        // files belonging to the torrents
        disconnect_all(errors::torrent_aborted);

        // post a message to the main thread to destruct
        // the torrent object from there
        if (m_owning_storage.get())
        {
            m_storage->abort_disk_io();
            m_storage->async_release_files(
                boost::bind(&torrent::on_cache_flushed, shared_from_this(), _1, _2));
        }
        else
        {
            if (alerts().should_post<cache_flushed_alert>())
                alerts().post_alert(cache_flushed_alert(get_handle()));
        }

        dequeue_torrent_check();

        if (m_state == torrent_status::checking_files)
            set_state(torrent_status::queued_for_checking);

        m_owning_storage = 0;
        m_ses.m_host_resolver.cancel();
    }

    void torrent::super_seeding(bool on)
    {
        if (on == m_super_seeding) return;

        // don't turn on super seeding if we're not a seed
        TORRENT_ASSERT(!on || is_seed() || !m_files_checked);
        if (on && !is_seed() && m_files_checked) return;
        m_super_seeding = on;

        if (m_super_seeding) return;

        // disable super seeding for all peers
        for (peer_iterator i = begin(); i != end(); ++i)
        {
            (*i)->superseed_piece(-1);
        }
    }

    int torrent::get_piece_to_super_seed(bitfield const& bits)
    {
        // return a piece with low availability that is not in
        // the bitfield and that is not currently being super
        // seeded by any peer
        TORRENT_ASSERT(m_super_seeding);

        // do a linear search from the first piece
        int min_availability = 9999;
        std::vector<int> avail_vec;
        for (int i = 0; i < m_torrent_file->num_pieces(); ++i)
        {
            if (bits[i]) continue;

            int availability = 0;
            for (const_peer_iterator j = begin(); j != end(); ++j)
            {
                if ((*j)->superseed_piece() == i)
                {
                    // avoid superseeding the same piece to more than one
                    // peer if we can avoid it. Do this by artificially
                    // increase the availability
                    availability = 999;
                    break;
                }
                if ((*j)->has_piece(i)) ++availability;
            }
            if (availability > min_availability) continue;
            if (availability == min_availability)
            {
                avail_vec.push_back(i);
                continue;
            }
            TORRENT_ASSERT(availability < min_availability);
            min_availability = availability;
            avail_vec.clear();
            avail_vec.push_back(i);
        }

        if (min_availability > 1)
        {
            // if the minimum availability is 2 or more,
            // we shouldn't be super seeding any more
            super_seeding(false);
            return -1;
        }

        return avail_vec[random() % avail_vec.size()];
    }

    void torrent::on_files_deleted(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (ret != 0)
        {
            if (alerts().should_post<torrent_delete_failed_alert>())
                alerts().post_alert(torrent_delete_failed_alert(get_handle(), j.error));
        }
        else
        {
            if (alerts().should_post<torrent_deleted_alert>())
                alerts().post_alert(torrent_deleted_alert(get_handle(), m_torrent_file->info_hash()));
        }
    }

    void torrent::on_files_released(int ret, disk_io_job const& j)
    {
/*
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (alerts().should_post<torrent_paused_alert>())
        {
            alerts().post_alert(torrent_paused_alert(get_handle()));
        }
*/
    }

    void torrent::on_save_resume_data(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (!j.resume_data)
        {
            alerts().post_alert(save_resume_data_failed_alert(get_handle(), j.error));
        }
        else
        {
            m_need_save_resume_data = false;
            m_last_saved_resume = time(0);
            write_resume_data(*j.resume_data);
            alerts().post_alert(save_resume_data_alert(j.resume_data
                , get_handle()));
        }
    }

    void torrent::on_file_renamed(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (ret == 0)
        {
            if (alerts().should_post<file_renamed_alert>())
                alerts().post_alert(file_renamed_alert(get_handle(), j.str, j.piece));
            m_torrent_file->rename_file(j.piece, j.str);
        }
        else
        {
            if (alerts().should_post<file_rename_failed_alert>())
                alerts().post_alert(file_rename_failed_alert(get_handle()
                    , j.piece, j.error));
        }
    }

    void torrent::on_torrent_paused(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (alerts().should_post<torrent_paused_alert>())
            alerts().post_alert(torrent_paused_alert(get_handle()));
    }

    std::string torrent::tracker_login() const
    {
        if (m_username.empty() && m_password.empty()) return "";
        return m_username + ":" + m_password;
    }

    void torrent::set_piece_deadline(int piece, int t, int flags)
    {
        ptime deadline = time_now() + milliseconds(t);

        if (is_seed() || m_picker->have_piece(piece))
        {
            if (flags & torrent_handle::alert_when_available)
                read_piece(piece);
            return;
        }

        for (std::list<time_critical_piece>::iterator i = m_time_critical_pieces.begin()
            , end(m_time_critical_pieces.end()); i != end; ++i)
        {
            if (i->piece != piece) continue;
            i->deadline = deadline;
            i->flags = flags;

            // resort i since deadline might have changed
            while (boost::next(i) != m_time_critical_pieces.end() && i->deadline > boost::next(i)->deadline)
            {
                std::iter_swap(i, boost::next(i));
                ++i;
            }
            while (i != m_time_critical_pieces.begin() && i->deadline < boost::prior(i)->deadline)
            {
                std::iter_swap(i, boost::next(i));
                --i;
            }
            return;
        }

        time_critical_piece p;
        p.first_requested = min_time();
        p.last_requested = min_time();
        p.flags = flags;
        p.deadline = deadline;
        p.peers = 0;
        p.piece = piece;
        std::list<time_critical_piece>::iterator i = std::upper_bound(m_time_critical_pieces.begin()
            , m_time_critical_pieces.end(), p);
        m_time_critical_pieces.insert(i, p);

        piece_picker::downloading_piece pi;
        m_picker->piece_info(piece, pi);
        if (pi.requested == 0) return;
        // this means we have outstanding requests (or queued
        // up requests that haven't been sent yet). Promote them
        // to deadline pieces immediately
        std::vector<void*> downloaders;
        m_picker->get_downloaders(downloaders, piece);

        int block = 0;
        for (std::vector<void*>::iterator i = downloaders.begin()
            , end(downloaders.end()); i != end; ++i, ++block)
        {
            policy::peer* p = (policy::peer*)*i;
            if (p == 0 || p->connection == 0) continue;
            p->connection->make_time_critical(piece_block(piece, block));
        }
    }

    void torrent::reset_piece_deadline(int piece)
    {
        remove_time_critical_piece(piece);
    }

    void torrent::remove_time_critical_piece(int piece, bool finished)
    {
        for (std::list<time_critical_piece>::iterator i = m_time_critical_pieces.begin()
            , end(m_time_critical_pieces.end()); i != end; ++i)
        {
            if (i->piece != piece) continue;
            if (finished)
            {
                if (i->flags & torrent_handle::alert_when_available)
                {
                    read_piece(i->piece);
                }

                // update the average download time and average
                // download time deviation
                int dl_time = total_milliseconds(time_now() - i->first_requested);

                if (m_average_piece_time == 0)
                {
                    m_average_piece_time = dl_time;
                }
                else
                {
                    int diff = abs(int(dl_time - m_average_piece_time));
                    if (m_piece_time_deviation == 0) m_piece_time_deviation = diff;
                    else m_piece_time_deviation = (m_piece_time_deviation * 6 + diff * 4) / 10;

                    m_average_piece_time = (m_average_piece_time * 6 + dl_time * 4) / 10;
                }
            }
            m_time_critical_pieces.erase(i);
            return;
        }
    }

    // remove time critical pieces where priority is 0
    void torrent::remove_time_critical_pieces(std::vector<int> const& priority)
    {
        for (std::list<time_critical_piece>::iterator i = m_time_critical_pieces.begin();
            i != m_time_critical_pieces.end();)
        {
            if (priority[i->piece] == 0)
            {
                i = m_time_critical_pieces.erase(i);
                continue;
            }
            ++i;
        }
    }

    void torrent::piece_availability(std::vector<int>& avail) const
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(valid_metadata());
        if (is_seed())
        {
            avail.clear();
            return;
        }

        m_picker->get_availability(avail);
    }

    void torrent::set_piece_priority(int index, int priority)
    {
//		INVARIANT_CHECK;

        TORRENT_ASSERT(valid_metadata());
        if (is_seed()) return;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(m_picker.get());
        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < m_torrent_file->num_pieces());
        if (index < 0 || index >= m_torrent_file->num_pieces()) return;

        bool was_finished = is_finished();
        bool filter_updated = m_picker->set_piece_priority(index, priority);
        TORRENT_ASSERT(num_have() >= m_picker->num_have_filtered());
        if (filter_updated)
        {
            update_peer_interest(was_finished);
            if (priority == 0) remove_time_critical_piece(index);
        }

    }

    int torrent::piece_priority(int index) const
    {
//		INVARIANT_CHECK;

        TORRENT_ASSERT(valid_metadata());
        if (is_seed()) return 1;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(m_picker.get());
        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < m_torrent_file->num_pieces());
        if (index < 0 || index >= m_torrent_file->num_pieces()) return 0;

        return m_picker->piece_priority(index);
    }

    void torrent::prioritize_pieces(std::vector<int> const& pieces)
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(valid_metadata());
        if (is_seed()) return;

        TORRENT_ASSERT(m_picker.get());

        int index = 0;
        bool filter_updated = false;
        bool was_finished = is_finished();
        for (std::vector<int>::const_iterator i = pieces.begin()
            , end(pieces.end()); i != end; ++i, ++index)
        {
            TORRENT_ASSERT(*i >= 0);
            TORRENT_ASSERT(*i <= 7);
            filter_updated |= m_picker->set_piece_priority(index, *i);
            TORRENT_ASSERT(num_have() >= m_picker->num_have_filtered());
        }
        if (filter_updated)
        {
            // we need to save this new state
            m_need_save_resume_data = true;

            update_peer_interest(was_finished);
            remove_time_critical_pieces(pieces);
        }
    }

    void torrent::piece_priorities(std::vector<int>* pieces) const
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(valid_metadata());
        if (is_seed())
        {
            pieces->clear();
            pieces->resize(m_torrent_file->num_pieces(), 1);
            return;
        }

        TORRENT_ASSERT(m_picker.get());
        m_picker->piece_priorities(*pieces);
    }

    namespace
    {
        void set_if_greater(int& piece_prio, int file_prio)
        {
            if (file_prio > piece_prio) piece_prio = file_prio;
        }
    }

    void torrent::prioritize_files(std::vector<int> const& files)
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        if (!valid_metadata() || is_seed()) return;

        // the bitmask need to have exactly one bit for every file
        // in the torrent
        TORRENT_ASSERT(int(files.size()) == m_torrent_file->num_files());

        if (m_torrent_file->num_pieces() == 0) return;

        int limit = int(files.size());
        if (valid_metadata() && limit > m_torrent_file->num_files())
            limit = m_torrent_file->num_files();

        if (m_file_priority.size() < limit)
            m_file_priority.resize(limit);

        std::copy(files.begin(), files.begin() + limit, m_file_priority.begin());

        if (valid_metadata() && m_torrent_file->num_files() > int(m_file_priority.size()))
            m_file_priority.resize(m_torrent_file->num_files(), 1);

        update_piece_priorities();
    }

    void torrent::set_file_priority(int index, int prio)
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        if (!valid_metadata() || is_seed()) return;

        TORRENT_ASSERT(index < m_torrent_file->num_files());
        TORRENT_ASSERT(index >= 0);
        if (index < 0 || index >= m_torrent_file->num_files()) return;
        if (m_file_priority[index] == prio) return;
        m_file_priority[index] = prio;
        update_piece_priorities();
    }

    int torrent::file_priority(int index) const
    {
        // this call is only valid on torrents with metadata
        if (!valid_metadata()) return 1;

        TORRENT_ASSERT(index < m_torrent_file->num_files());
        TORRENT_ASSERT(index >= 0);
        if (index < 0 || index >= m_torrent_file->num_files()) return 0;
        return m_file_priority[index];
    }

    void torrent::file_priorities(std::vector<int>* files) const
    {
        INVARIANT_CHECK;
        if (!valid_metadata())
        {
            files->resize(m_file_priority.size());
            std::copy(m_file_priority.begin(), m_file_priority.end(), files->begin());
            return;
        }

        files->resize(m_torrent_file->num_files());
        std::copy(m_file_priority.begin(), m_file_priority.end(), files->begin());
        if (m_file_priority.size() < m_torrent_file->num_files())
            std::fill(files->begin() + m_file_priority.size(), files->end(), 1);
    }

    void torrent::update_piece_priorities()
    {
        INVARIANT_CHECK;

        if (m_torrent_file->num_pieces() == 0) return;

        size_type position = 0;
        int piece_length = m_torrent_file->piece_length();
        // initialize the piece priorities to 0, then only allow
        // setting higher priorities
        std::vector<int> pieces(m_torrent_file->num_pieces(), 0);
        for (int i = 0; i < int(m_file_priority.size()); ++i)
        {
            size_type start = position;
            size_type size = m_torrent_file->files().at(i).size;
            if (size == 0) continue;
            position += size;
            if (m_file_priority[i] == 0) continue;

            // mark all pieces of the file with this file's priority
            // but only if the priority is higher than the pieces
            // already set (to avoid problems with overlapping pieces)
            int start_piece = int(start / piece_length);
            int last_piece = int((position - 1) / piece_length);
            TORRENT_ASSERT(last_piece < int(pieces.size()));
            // if one piece spans several files, we might
            // come here several times with the same start_piece, end_piece
            std::for_each(pieces.begin() + start_piece
                , pieces.begin() + last_piece + 1
                , boost::bind(&set_if_greater, _1, m_file_priority[i]));
        }
        prioritize_pieces(pieces);
    }

    // this is called when piece priorities have been updated
    // updates the interested flag in peers
    void torrent::update_peer_interest(bool was_finished)
    {
        for (peer_iterator i = begin(); i != end();)
        {
            peer_connection* p = *i;
            // update_interest may disconnect the peer and
            // invalidate the iterator
            ++i;
            p->update_interest();
        }

        // the torrent just became finished
        if (is_finished() && !was_finished)
        {
            finished();
        }
        else if (!is_finished() && was_finished)
        {
            // if we used to be finished, but we aren't anymore
            // we may need to connect to peers again
            resume_download();
        }
    }

    void torrent::filter_piece(int index, bool filter)
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(valid_metadata());
        if (is_seed()) return;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(m_picker.get());
        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < m_torrent_file->num_pieces());

        if (index < 0 || index >= m_torrent_file->num_pieces()) return;

        bool was_finished = is_finished();
        m_picker->set_piece_priority(index, filter ? 1 : 0);
        update_peer_interest(was_finished);
    }

    void torrent::filter_pieces(std::vector<bool> const& bitmask)
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(valid_metadata());
        if (is_seed()) return;

        TORRENT_ASSERT(m_picker.get());

        bool was_finished = is_finished();
        int index = 0;
        for (std::vector<bool>::const_iterator i = bitmask.begin()
            , end(bitmask.end()); i != end; ++i, ++index)
        {
            if ((m_picker->piece_priority(index) == 0) == *i) continue;
            if (*i)
                m_picker->set_piece_priority(index, 0);
            else
                m_picker->set_piece_priority(index, 1);
        }
        update_peer_interest(was_finished);
    }

    bool torrent::is_piece_filtered(int index) const
    {
        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(valid_metadata());
        if (is_seed()) return false;

        TORRENT_ASSERT(m_picker.get());
        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < m_torrent_file->num_pieces());

        if (index < 0 || index >= m_torrent_file->num_pieces()) return true;

        return m_picker->piece_priority(index) == 0;
    }

    void torrent::filtered_pieces(std::vector<bool>& bitmask) const
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        TORRENT_ASSERT(valid_metadata());
        if (is_seed())
        {
            bitmask.clear();
            bitmask.resize(m_torrent_file->num_pieces(), false);
            return;
        }

        TORRENT_ASSERT(m_picker.get());
        m_picker->filtered_pieces(bitmask);
    }

    void torrent::filter_files(std::vector<bool> const& bitmask)
    {
        INVARIANT_CHECK;

        // this call is only valid on torrents with metadata
        if (!valid_metadata() || is_seed()) return;

        // the bitmask need to have exactly one bit for every file
        // in the torrent
        TORRENT_ASSERT((int)bitmask.size() == m_torrent_file->num_files());

        if (int(bitmask.size()) != m_torrent_file->num_files()) return;

        size_type position = 0;

        if (m_torrent_file->num_pieces())
        {
            int piece_length = m_torrent_file->piece_length();
            // mark all pieces as filtered, then clear the bits for files
            // that should be downloaded
            std::vector<bool> piece_filter(m_torrent_file->num_pieces(), true);
            for (int i = 0; i < (int)bitmask.size(); ++i)
            {
                size_type start = position;
                position += m_torrent_file->files().at(i).size;
                // is the file selected for download?
                if (!bitmask[i])
                {
                    // mark all pieces of the file as downloadable
                    int start_piece = int(start / piece_length);
                    int last_piece = int(position / piece_length);
                    // if one piece spans several files, we might
                    // come here several times with the same start_piece, end_piece
                    std::fill(piece_filter.begin() + start_piece, piece_filter.begin()
                        + last_piece + 1, false);
                }
            }
            filter_pieces(piece_filter);
        }
    }

    void torrent::replace_trackers(std::vector<announce_entry> const& urls)
    {
        m_trackers.clear();
        std::remove_copy_if(urls.begin(), urls.end(), back_inserter(m_trackers)
            , boost::bind(&std::string::empty, boost::bind(&announce_entry::url, _1)));

        m_last_working_tracker = -1;
        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
            if (i->source == 0) i->source = announce_entry::source_client;

        if (settings().prefer_udp_trackers)
            prioritize_udp_trackers();

        if (!m_trackers.empty()) announce_with_tracker();
    }

    void torrent::prioritize_udp_trackers()
    {
        // look for udp-trackers
        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
        {
            if (i->url.substr(0, 6) != "udp://") continue;
            // now, look for trackers with the same hostname
            // that is has higher priority than this one
            // if we find one, swap with the udp-tracker
            error_code ec;
            std::string udp_hostname;
            using boost::tuples::ignore;
            boost::tie(ignore, ignore, udp_hostname, ignore, ignore)
                = parse_url_components(i->url, ec);
            for (std::vector<announce_entry>::iterator j = m_trackers.begin();
                j != i; ++j)
            {
                std::string hostname;
                boost::tie(ignore, ignore, hostname, ignore, ignore)
                    = parse_url_components(j->url, ec);
                if (hostname != udp_hostname) continue;
                if (j->url.substr(0, 6) == "udp://") continue;
                using std::swap;
                using std::iter_swap;
                swap(i->tier, j->tier);
                iter_swap(i, j);
                break;
            }
        }
    }

    void torrent::add_tracker(announce_entry const& url)
    {
        std::vector<announce_entry>::iterator k = std::find_if(m_trackers.begin()
            , m_trackers.end(), boost::bind(&announce_entry::url, _1) == url.url);
        if (k != m_trackers.end())
        {
            k->source |= url.source;
            return;
        }
        k = std::upper_bound(m_trackers.begin(), m_trackers.end(), url
            , boost::bind(&announce_entry::tier, _1) < boost::bind(&announce_entry::tier, _2));
        if (k - m_trackers.begin() < m_last_working_tracker) ++m_last_working_tracker;
        k = m_trackers.insert(k, url);
        if (k->source == 0) k->source = announce_entry::source_client;
        if (!m_trackers.empty()) announce_with_tracker();
    }

    bool torrent::choke_peer(peer_connection& c)
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(!c.is_choked());
        TORRENT_ASSERT(!c.ignore_unchoke_slots());
        TORRENT_ASSERT(m_num_uploads > 0);
        if (!c.send_choke()) return false;
        --m_num_uploads;
        return true;
    }

    bool torrent::unchoke_peer(peer_connection& c, bool optimistic)
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(!m_graceful_pause_mode);
        TORRENT_ASSERT(c.is_choked());
        TORRENT_ASSERT(!c.ignore_unchoke_slots());
        // when we're unchoking the optimistic slots, we might
        // exceed the limit temporarily while we're iterating
        // over the peers
        if (m_num_uploads >= m_max_uploads && !optimistic) return false;
        if (!c.send_unchoke()) return false;
        ++m_num_uploads;
        return true;
    }

    void torrent::cancel_block(piece_block block)
    {
        INVARIANT_CHECK;

        for (peer_iterator i = m_connections.begin()
            , end(m_connections.end()); i != end; ++i)
        {
            (*i)->cancel_request(block);
        }
    }

#ifdef TORRENT_USE_OPENSSL
    std::string password_callback(int length, boost::asio::ssl::context::password_purpose p
        , std::string pw)
    {
        if (p != boost::asio::ssl::context::for_reading) return "";
        return pw;
    }

    // certificate is a filename to a .pem file which is our
    // certificate. The certificate must be signed by the root
    // cert of the torrent file. any peer we connect to or that
    // connect to use must present a valid certificate signed
    // by the torrent root cert as well
    void torrent::set_ssl_cert(std::string const& certificate
        , std::string const& private_key
        , std::string const& dh_params
        , std::string const& passphrase)
    {
        if (!m_ssl_ctx) return;

        using boost::asio::ssl::context;
        error_code ec;
        m_ssl_ctx->set_password_callback(boost::bind(&password_callback, _1, _2, passphrase), ec);
        if (ec)
        {
            if (alerts().should_post<torrent_error_alert>())
                alerts().post_alert(torrent_error_alert(get_handle(), ec));
        }
        m_ssl_ctx->use_certificate_file(certificate, context::pem, ec);
        if (ec)
        {
            if (alerts().should_post<torrent_error_alert>())
                alerts().post_alert(torrent_error_alert(get_handle(), ec));
        }
        m_ssl_ctx->use_private_key_file(private_key, context::pem, ec);
        if (ec)
        {
            if (alerts().should_post<torrent_error_alert>())
                alerts().post_alert(torrent_error_alert(get_handle(), ec));
        }
        m_ssl_ctx->use_tmp_dh_file(dh_params, ec);
        if (ec)
        {
            if (alerts().should_post<torrent_error_alert>())
                alerts().post_alert(torrent_error_alert(get_handle(), ec));
        }
    }
#endif

    void torrent::remove_peer(peer_connection* p)
    {
//		INVARIANT_CHECK;

        TORRENT_ASSERT(p != 0);
        TORRENT_ASSERT(m_ses.is_network_thread());

        peer_iterator i = m_connections.find(p);
        if (i == m_connections.end())
        {
            TORRENT_ASSERT(false);
            return;
        }

        if (ready_for_connections())
        {
            TORRENT_ASSERT(p->associated_torrent().lock().get() == this);

            if (p->is_seed())
            {
                if (m_picker.get())
                {
                    m_picker->dec_refcount_all();
                }
            }
            else
            {
                if (m_picker.get())
                {
                    bitfield const& pieces = p->get_bitfield();
                    TORRENT_ASSERT(pieces.count() <= int(pieces.size()));
                    m_picker->dec_refcount(pieces);
                }
            }
        }

        if (!p->is_choked() && !p->ignore_unchoke_slots())
        {
            --m_num_uploads;
            m_ses.m_unchoke_time_scaler = 0;
        }

        policy::peer* pp = p->peer_info_struct();
        if (pp)
        {
            if (pp->optimistically_unchoked)
                m_ses.m_optimistic_unchoke_time_scaler = 0;

            // if the share ratio is 0 (infinite), the
            // m_available_free_upload isn't used,
            // because it isn't necessary.
            if (ratio() != 0.f)
            {
                TORRENT_ASSERT(p->associated_torrent().lock().get() == this);
                TORRENT_ASSERT(p->share_diff() < (std::numeric_limits<size_type>::max)());
                add_free_upload(p->share_diff());
            }
            TORRENT_ASSERT(pp->prev_amount_upload == 0);
            TORRENT_ASSERT(pp->prev_amount_download == 0);
            pp->prev_amount_download += p->statistics().total_payload_download() >> 10;
            pp->prev_amount_upload += p->statistics().total_payload_upload() >> 10;
        }

        m_policy.connection_closed(*p, m_ses.session_time());
        p->set_peer_info(0);
        TORRENT_ASSERT(i != m_connections.end());
        m_connections.erase(i);
    }

    void torrent::remove_web_seed(std::list<web_seed_entry>::iterator web)
    {
        if (web->resolving)
        {
            web->removed = true;
            return;
        }
        m_web_seeds.erase(web);
    }

    void torrent::connect_to_url_seed(std::list<web_seed_entry>::iterator web)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        TORRENT_ASSERT(!web->resolving);
        if (web->resolving) return;

        if (int(m_connections.size()) >= m_max_connections
            || m_ses.num_connections() >= m_ses.settings().connections_limit)
            return;

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
        (*m_ses.m_logger) << time_now_string() << " resolving web seed: " << web->url << "\n";
#endif

        std::string protocol;
        std::string auth;
        std::string hostname;
        int port;
        std::string path;
        error_code ec;
        boost::tie(protocol, auth, hostname, port, path)
            = parse_url_components(web->url, ec);

        if (ec)
        {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
            (*m_ses.m_logger) << time_now_string() << " failed to parse web seed url: " << ec.message() << "\n";
#endif
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                    url_seed_alert(get_handle(), web->url, ec));
            }
            // never try it again
            remove_web_seed(web);
            return;
        }

#ifdef TORRENT_USE_OPENSSL
        if (protocol != "http" && protocol != "https")
#else
        if (protocol != "http")
#endif
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                    url_seed_alert(get_handle(), web->url, errors::unsupported_url_protocol));
            }
            // never try it again
            remove_web_seed(web);
            return;
        }

        if (hostname.empty())
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                    url_seed_alert(get_handle(), web->url, errors::invalid_hostname));
            }
            // never try it again
            remove_web_seed(web);
            return;
        }

        if (port == 0)
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                    url_seed_alert(get_handle(), web->url, errors::invalid_port));
            }
            // never try it again
            remove_web_seed(web);
            return;
        }

        if (m_ses.m_port_filter.access(port) & port_filter::blocked)
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                url_seed_alert(get_handle(), web->url, errors::port_blocked));
            }
            // never try it again
            remove_web_seed(web);
            return;
        }

        if (web->endpoint.port() != 0)
        {
            connect_web_seed(web, web->endpoint);
            return;
        }

        proxy_settings const& ps = m_ses.proxy();
        if (ps.type == proxy_settings::http
            || ps.type == proxy_settings::http_pw)
        {
            // use proxy
            tcp::resolver::query q(ps.hostname, to_string(ps.port).elems);
            m_ses.m_host_resolver.async_resolve(q,
                boost::bind(&torrent::on_proxy_name_lookup, shared_from_this(), _1, _2, web));
        }
        else if (ps.proxy_hostnames
            && (ps.type == proxy_settings::socks5
                || ps.type == proxy_settings::socks5_pw))
        {
            connect_web_seed(web, tcp::endpoint(address(), port));
        }
        else
        {
            web->resolving = true;
            tcp::resolver::query q(hostname, to_string(port).elems);
            m_ses.m_host_resolver.async_resolve(q,
                boost::bind(&torrent::on_name_lookup, shared_from_this(), _1, _2, web
                    , tcp::endpoint()));
        }
    }

    void torrent::on_proxy_name_lookup(error_code const& e, tcp::resolver::iterator host
        , std::list<web_seed_entry>::iterator web)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
        (*m_ses.m_logger) << time_now_string() << " completed resolve proxy hostname for: " << web->url << "\n";
        if (e)
            *m_ses.m_logger << time_now_string() << " on_proxy_name_lookup: " << e.message() << "\n";
#endif

        if (m_abort) return;

        if (e || host == tcp::resolver::iterator())
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                    url_seed_alert(get_handle(), web->url, e));
            }

            // the name lookup failed for the http host. Don't try
            // this host again
            remove_web_seed(web);
            return;
        }

        if (m_ses.is_aborted()) return;

        if (int(m_connections.size()) >= m_max_connections
            || m_ses.num_connections() >= m_ses.settings().connections_limit)
            return;

        tcp::endpoint a(host->endpoint());

        using boost::tuples::ignore;
        std::string hostname;
        int port;
        error_code ec;
        boost::tie(ignore, ignore, hostname, port, ignore)
            = parse_url_components(web->url, ec);

        if (ec)
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
            {
                m_ses.m_alerts.post_alert(
                    url_seed_alert(get_handle(), web->url, ec));
            }
            remove_web_seed(web);
            return;
        }

        if (m_apply_ip_filter
            && m_ses.m_ip_filter.access(a.address()) & ip_filter::blocked)
        {
            if (m_ses.m_alerts.should_post<peer_blocked_alert>())
                m_ses.m_alerts.post_alert(peer_blocked_alert(get_handle(), a.address()));
            return;
        }

        web->resolving = true;
        tcp::resolver::query q(hostname, to_string(port).elems);
        m_ses.m_host_resolver.async_resolve(q,
            boost::bind(&torrent::on_name_lookup, shared_from_this(), _1, _2, web, a));
    }

    void torrent::on_name_lookup(error_code const& e, tcp::resolver::iterator host
        , std::list<web_seed_entry>::iterator web, tcp::endpoint proxy)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

        TORRENT_ASSERT(web->resolving == true);
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
        (*m_ses.m_logger) << time_now_string() << " completed resolve: " << web->url << "\n";
#endif
        web->resolving = false;
        if (web->removed)
        {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
            (*m_ses.m_logger) << time_now_string() << " removed web seed\n";
#endif
            remove_web_seed(web);
            return;
        }

        if (m_abort) return;

        if (e || host == tcp::resolver::iterator())
        {
            if (m_ses.m_alerts.should_post<url_seed_alert>())
                m_ses.m_alerts.post_alert(url_seed_alert(get_handle(), web->url, e));
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
            (*m_ses.m_logger) << " ** HOSTNAME LOOKUP FAILED!**: " << web->url
                << " " << e.message() << "\n";
#endif

            // unavailable, retry in 30 minutes
            web->retry = time_now() + minutes(30);
            return;
        }

        if (int(m_connections.size()) >= m_max_connections
            || m_ses.num_connections() >= m_ses.settings().connections_limit)
            return;

        tcp::endpoint a(host->endpoint());
        connect_web_seed(web, a);
    }

    void torrent::connect_web_seed(std::list<web_seed_entry>::iterator web, tcp::endpoint a)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (m_apply_ip_filter
            && m_ses.m_ip_filter.access(a.address()) & ip_filter::blocked)
        {
            if (m_ses.m_alerts.should_post<peer_blocked_alert>())
                m_ses.m_alerts.post_alert(peer_blocked_alert(get_handle(), a.address()));
            return;
        }

        TORRENT_ASSERT(web->resolving == false);
        TORRENT_ASSERT(web->connection == 0);

        web->endpoint = a;

        if (is_paused()) return;
        if (m_ses.is_aborted()) return;

        boost::shared_ptr<socket_type> s(new (std::nothrow) socket_type(m_ses.m_io_service));
        if (!s) return;

        bool ssl = string_begins_no_case("https://", web->url.c_str());
        void* userdata = 0;
#ifdef TORRENT_USE_OPENSSL
        if (ssl)
        {
            userdata = m_ssl_ctx.get();
            if (!userdata) userdata = &m_ses.m_ssl_ctx;
        }
#endif
        bool ret = instantiate_connection(m_ses.m_io_service, m_ses.proxy(), *s, userdata, 0, true);
        (void)ret;
        TORRENT_ASSERT(ret);

        proxy_settings const& ps = m_ses.proxy();
        if ((ps.type == proxy_settings::http
            || ps.type == proxy_settings::http_pw)
            && !ssl)
        {
            // the web seed connection will talk immediately to
            // the proxy, without requiring CONNECT support
            s->get<http_stream>()->set_no_connect(true);
        }

        if (ps.proxy_hostnames
            && (ps.type == proxy_settings::socks5
                || ps.type == proxy_settings::socks5_pw))
        {
            // we're using a socks proxy and we're resolving
            // hostnames through it
            socks5_stream* str =
#ifdef TORRENT_USE_OPENSSL
                ssl ? &s->get<ssl_stream<socks5_stream> >()->next_layer() :
#endif
                s->get<socks5_stream>();
            TORRENT_ASSERT(str);

            using boost::tuples::ignore;
            std::string hostname;
            error_code ec;
            boost::tie(ignore, ignore, hostname, ignore, ignore)
                = parse_url_components(web->url, ec);
            str->set_dst_name(hostname);
        }

        boost::intrusive_ptr<peer_connection> c;
        if (web->type == web_seed_entry::url_seed)
        {
            c = new (std::nothrow) web_peer_connection(
                m_ses, shared_from_this(), s, a, web->url, 0, // TODO: pass in web
                web->auth, web->extra_headers);
        }
        else if (web->type == web_seed_entry::http_seed)
        {
            c = new (std::nothrow) http_seed_connection(
                m_ses, shared_from_this(), s, a, web->url, 0, // TODO: pass in web
                web->auth, web->extra_headers);
        }
        if (!c) return;

#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        c->m_in_constructor = false;
#endif

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            boost::shared_ptr<peer_plugin>
                pp((*i)->new_connection(c.get()));
            if (pp) c->add_extension(pp);
        }
#endif

        TORRENT_TRY
        {
            // add the newly connected peer to this torrent's peer list
            m_connections.insert(boost::get_pointer(c));
            m_ses.m_connections.insert(c);

            TORRENT_ASSERT(!web->connection);
            web->connection = c.get();

#if defined TORRENT_VERBOSE_LOGGING
            (*m_ses.m_logger) << time_now_string() << " web seed connection started " << web->url << "\n";
#endif

            c->start();

            m_ses.m_half_open.enqueue(
                boost::bind(&peer_connection::on_connect, c, _1)
                , boost::bind(&peer_connection::on_timeout, c)
                , seconds(settings().peer_connect_timeout));
        }
        TORRENT_CATCH (std::exception& e)
        {
            TORRENT_DECLARE_DUMMY(std::exception, e);
            (void)e;
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
            (*m_ses.m_logger) << " ** HOSTNAME LOOKUP FAILED!**: " << e.what() << "\n";
#endif
            c->disconnect(errors::no_error, 1);
        }
    }

#ifndef TORRENT_DISABLE_RESOLVE_COUNTRIES
    namespace
    {
        unsigned long swap_bytes(unsigned long a)
        {
            return (a >> 24) | ((a & 0xff0000) >> 8) | ((a & 0xff00) << 8) | ((a & 0xff) << 24);
        }
    }

    void torrent::resolve_peer_country(boost::intrusive_ptr<peer_connection> const& p) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (m_resolving_country
            || is_local(p->remote().address())
            || p->has_country()
            || p->is_connecting()
            || p->is_queued()
            || p->in_handshake()
            || p->remote().address().is_v6()) return;

        asio::ip::address_v4 reversed(swap_bytes(p->remote().address().to_v4().to_ulong()));
        error_code ec;
        tcp::resolver::query q(reversed.to_string(ec) + ".zz.countries.nerd.dk", "0");
        if (ec)
        {
            p->set_country("!!");
            return;
        }
        m_resolving_country = true;
        m_ses.m_host_resolver.async_resolve(q,
            boost::bind(&torrent::on_country_lookup, shared_from_this(), _1, _2, p));
    }

    namespace
    {
        struct country_entry
        {
            int code;
            char const* name;
        };
    }

    void torrent::on_country_lookup(error_code const& error, tcp::resolver::iterator i
        , intrusive_ptr<peer_connection> p) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

        m_resolving_country = false;

        if (m_abort) return;

        // must be ordered in increasing order
        static const country_entry country_map[] =
        {
              {  4,  "AF"}, {  8,  "AL"}, { 10,  "AQ"}, { 12,  "DZ"}, { 16,  "AS"}
            , { 20,  "AD"}, { 24,  "AO"}, { 28,  "AG"}, { 31,  "AZ"}, { 32,  "AR"}
            , { 36,  "AU"}, { 40,  "AT"}, { 44,  "BS"}, { 48,  "BH"}, { 50,  "BD"}
            , { 51,  "AM"}, { 52,  "BB"}, { 56,  "BE"}, { 60,  "BM"}, { 64,  "BT"}
            , { 68,  "BO"}, { 70,  "BA"}, { 72,  "BW"}, { 74,  "BV"}, { 76,  "BR"}
            , { 84,  "BZ"}, { 86,  "IO"}, { 90,  "SB"}, { 92,  "VG"}, { 96,  "BN"}
            , {100,  "BG"}, {104,  "MM"}, {108,  "BI"}, {112,  "BY"}, {116,  "KH"}
            , {120,  "CM"}, {124,  "CA"}, {132,  "CV"}, {136,  "KY"}, {140,  "CF"}
            , {144,  "LK"}, {148,  "TD"}, {152,  "CL"}, {156,  "CN"}, {158,  "TW"}
            , {162,  "CX"}, {166,  "CC"}, {170,  "CO"}, {174,  "KM"}, {175,  "YT"}
            , {178,  "CG"}, {180,  "CD"}, {184,  "CK"}, {188,  "CR"}, {191,  "HR"}
            , {192,  "CU"}, {203,  "CZ"}, {204,  "BJ"}, {208,  "DK"}, {212,  "DM"}
            , {214,  "DO"}, {218,  "EC"}, {222,  "SV"}, {226,  "GQ"}, {231,  "ET"}
            , {232,  "ER"}, {233,  "EE"}, {234,  "FO"}, {238,  "FK"}, {239,  "GS"}
            , {242,  "FJ"}, {246,  "FI"}, {248,  "AX"}, {250,  "FR"}, {254,  "GF"}
            , {258,  "PF"}, {260,  "TF"}, {262,  "DJ"}, {266,  "GA"}, {268,  "GE"}
            , {270,  "GM"}, {275,  "PS"}, {276,  "DE"}, {288,  "GH"}, {292,  "GI"}
            , {296,  "KI"}, {300,  "GR"}, {304,  "GL"}, {308,  "GD"}, {312,  "GP"}
            , {316,  "GU"}, {320,  "GT"}, {324,  "GN"}, {328,  "GY"}, {332,  "HT"}
            , {334,  "HM"}, {336,  "VA"}, {340,  "HN"}, {344,  "HK"}, {348,  "HU"}
            , {352,  "IS"}, {356,  "IN"}, {360,  "ID"}, {364,  "IR"}, {368,  "IQ"}
            , {372,  "IE"}, {376,  "IL"}, {380,  "IT"}, {384,  "CI"}, {388,  "JM"}
            , {392,  "JP"}, {398,  "KZ"}, {400,  "JO"}, {404,  "KE"}, {408,  "KP"}
            , {410,  "KR"}, {414,  "KW"}, {417,  "KG"}, {418,  "LA"}, {422,  "LB"}
            , {426,  "LS"}, {428,  "LV"}, {430,  "LR"}, {434,  "LY"}, {438,  "LI"}
            , {440,  "LT"}, {442,  "LU"}, {446,  "MO"}, {450,  "MG"}, {454,  "MW"}
            , {458,  "MY"}, {462,  "MV"}, {466,  "ML"}, {470,  "MT"}, {474,  "MQ"}
            , {478,  "MR"}, {480,  "MU"}, {484,  "MX"}, {492,  "MC"}, {496,  "MN"}
            , {498,  "MD"}, {500,  "MS"}, {504,  "MA"}, {508,  "MZ"}, {512,  "OM"}
            , {516,  "NA"}, {520,  "NR"}, {524,  "NP"}, {528,  "NL"}, {530,  "AN"}
            , {533,  "AW"}, {540,  "NC"}, {548,  "VU"}, {554,  "NZ"}, {558,  "NI"}
            , {562,  "NE"}, {566,  "NG"}, {570,  "NU"}, {574,  "NF"}, {578,  "NO"}
            , {580,  "MP"}, {581,  "UM"}, {583,  "FM"}, {584,  "MH"}, {585,  "PW"}
            , {586,  "PK"}, {591,  "PA"}, {598,  "PG"}, {600,  "PY"}, {604,  "PE"}
            , {608,  "PH"}, {612,  "PN"}, {616,  "PL"}, {620,  "PT"}, {624,  "GW"}
            , {626,  "TL"}, {630,  "PR"}, {634,  "QA"}, {634,  "QA"}, {638,  "RE"}
            , {642,  "RO"}, {643,  "RU"}, {646,  "RW"}, {654,  "SH"}, {659,  "KN"}
            , {660,  "AI"}, {662,  "LC"}, {666,  "PM"}, {670,  "VC"}, {674,  "SM"}
            , {678,  "ST"}, {682,  "SA"}, {686,  "SN"}, {690,  "SC"}, {694,  "SL"}
            , {702,  "SG"}, {703,  "SK"}, {704,  "VN"}, {705,  "SI"}, {706,  "SO"}
            , {710,  "ZA"}, {716,  "ZW"}, {724,  "ES"}, {732,  "EH"}, {736,  "SD"}
            , {740,  "SR"}, {744,  "SJ"}, {748,  "SZ"}, {752,  "SE"}, {756,  "CH"}
            , {760,  "SY"}, {762,  "TJ"}, {764,  "TH"}, {768,  "TG"}, {772,  "TK"}
            , {776,  "TO"}, {780,  "TT"}, {784,  "AE"}, {788,  "TN"}, {792,  "TR"}
            , {795,  "TM"}, {796,  "TC"}, {798,  "TV"}, {800,  "UG"}, {804,  "UA"}
            , {807,  "MK"}, {818,  "EG"}, {826,  "GB"}, {834,  "TZ"}, {840,  "US"}
            , {850,  "VI"}, {854,  "BF"}, {858,  "UY"}, {860,  "UZ"}, {862,  "VE"}
            , {876,  "WF"}, {882,  "WS"}, {887,  "YE"}, {891,  "CS"}, {894,  "ZM"}
        };

        if (error || i == tcp::resolver::iterator())
        {
            // this is used to indicate that we shouldn't
            // try to resolve it again
            p->set_country("--");
            return;
        }

        while (i != tcp::resolver::iterator()
            && !i->endpoint().address().is_v4()) ++i;
        if (i != tcp::resolver::iterator())
        {
            // country is an ISO 3166 country code
            int country = i->endpoint().address().to_v4().to_ulong() & 0xffff;

            // look up the country code in the map
            const int size = sizeof(country_map)/sizeof(country_map[0]);
            country_entry tmp = {country, ""};
            country_entry const* j =
                std::lower_bound(country_map, country_map + size, tmp
                    , boost::bind(&country_entry::code, _1) < boost::bind(&country_entry::code, _2));
            if (j == country_map + size
                || j->code != country)
            {
                // unknown country!
                p->set_country("!!");
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                (*m_ses.m_logger) << "IP " << p->remote().address() << " was mapped to unknown country: " << country << "\n";
#endif
                return;
            }

            p->set_country(j->name);
        }
    }
#endif

    void torrent::read_resume_data(lazy_entry const& rd)
    {
        m_total_uploaded = rd.dict_find_int_value("total_uploaded");
        m_total_downloaded = rd.dict_find_int_value("total_downloaded");
        m_active_time = rd.dict_find_int_value("active_time");
        m_finished_time = rd.dict_find_int_value("finished_time");
        m_seeding_time = rd.dict_find_int_value("seeding_time");
        m_last_seen_complete = rd.dict_find_int_value("last_seen_complete");
        m_complete = rd.dict_find_int_value("num_seeds", 0xffffff);
        m_incomplete = rd.dict_find_int_value("num_incomplete", 0xffffff);
        m_downloaders = rd.dict_find_int_value("num_downloaders", 0xffffff);
        set_upload_limit(rd.dict_find_int_value("upload_rate_limit", -1));
        set_download_limit(rd.dict_find_int_value("download_rate_limit", -1));
        set_max_connections(rd.dict_find_int_value("max_connections", -1));
        set_max_uploads(rd.dict_find_int_value("max_uploads", -1));
        m_seed_mode = rd.dict_find_int_value("seed_mode", 0) && m_torrent_file->is_valid();
        if (m_seed_mode) m_verified.resize(m_torrent_file->num_pieces(), false);
        super_seeding(rd.dict_find_int_value("super_seeding", 0));

        m_last_scrape = rd.dict_find_int_value("last_scrape", 0);
        m_last_download = rd.dict_find_int_value("last_download", 0);
        m_last_upload = rd.dict_find_int_value("last_upload", 0);

        m_url = rd.dict_find_string_value("url");
        m_uuid = rd.dict_find_string_value("uuid");
        m_source_feed_url = rd.dict_find_string_value("feed");

        if (!m_uuid.empty() || !m_url.empty())
        {
            boost::shared_ptr<torrent> me(shared_from_this());

            // insert this torrent in the uuid index
            m_ses.m_uuids.insert(std::make_pair(m_uuid.empty()
                ? m_url : m_uuid, me));
        }

        m_added_time = rd.dict_find_int_value("added_time", m_added_time);
        m_completed_time = rd.dict_find_int_value("completed_time", m_completed_time);
        if (m_completed_time != 0 && m_completed_time < m_added_time)
            m_completed_time = m_added_time;

        lazy_entry const* file_priority = rd.dict_find_list("file_priority");
        if (file_priority && file_priority->list_size()
            == m_torrent_file->num_files())
        {
            for (int i = 0; i < file_priority->list_size(); ++i)
                m_file_priority[i] = file_priority->list_int_value_at(i, 1);
            update_piece_priorities();
        }

        lazy_entry const* piece_priority = rd.dict_find_string("piece_priority");
        if (piece_priority && piece_priority->string_length()
            == m_torrent_file->num_pieces())
        {
            char const* p = piece_priority->string_ptr();
            for (int i = 0; i < piece_priority->string_length(); ++i)
                m_picker->set_piece_priority(i, p[i]);
            m_policy.recalculate_connect_candidates();
        }

        if (!m_override_resume_data)
        {
            int auto_managed_ = rd.dict_find_int_value("auto_managed", -1);
            if (auto_managed_ != -1) m_auto_managed = auto_managed_;
        }

        int sequential_ = rd.dict_find_int_value("sequential_download", -1);
        if (sequential_ != -1) set_sequential_download(sequential_);

        if (!m_override_resume_data)
        {
            int paused_ = rd.dict_find_int_value("paused", -1);
            if (paused_ != -1)
            {
                m_allow_peers = !paused_;
                m_announce_to_dht = !paused_;
                m_announce_to_trackers = !paused_;
                m_announce_to_lsd = !paused_;
            }
            int dht_ = rd.dict_find_int_value("announce_to_dht", -1);
            if (dht_ != -1) m_announce_to_dht = dht_;
            int lsd_ = rd.dict_find_int_value("announce_to_lsd", -1);
            if (lsd_ != -1) m_announce_to_lsd = lsd_;
            int track_ = rd.dict_find_int_value("announce_to_trackers", -1);
            if (track_ != -1) m_announce_to_trackers = track_;
        }

        lazy_entry const* trackers = rd.dict_find_list("trackers");
        if (trackers)
        {
            if (!m_merge_resume_trackers) m_trackers.clear();
            int tier = 0;
            for (int i = 0; i < trackers->list_size(); ++i)
            {
                lazy_entry const* tier_list = trackers->list_at(i);
                if (tier_list == 0 || tier_list->type() != lazy_entry::list_t)
                    continue;
                for (int j = 0; j < tier_list->list_size(); ++j)
                {
                    announce_entry e(tier_list->list_string_value_at(j));
                    if (std::find_if(m_trackers.begin(), m_trackers.end()
                        , boost::bind(&announce_entry::url, _1) == e.url) != m_trackers.end())
                        continue;
                    e.tier = tier;
                    e.fail_limit = 0;
                    m_trackers.push_back(e);
                }
                ++tier;
            }
            std::sort(m_trackers.begin(), m_trackers.end(), boost::bind(&announce_entry::tier, _1)
                < boost::bind(&announce_entry::tier, _2));

            if (settings().prefer_udp_trackers)
                prioritize_udp_trackers();
        }

        lazy_entry const* url_list = rd.dict_find_list("url-list");
        if (url_list)
        {
            for (int i = 0; i < url_list->list_size(); ++i)
            {
                std::string url = url_list->list_string_value_at(i);
                if (url.empty()) continue;
                add_web_seed(url, web_seed_entry::url_seed);
            }
        }

        lazy_entry const* httpseeds = rd.dict_find_list("httpseeds");
        if (httpseeds)
        {
            for (int i = 0; i < httpseeds->list_size(); ++i)
            {
                std::string url = httpseeds->list_string_value_at(i);
                if (url.empty()) continue;
                add_web_seed(url, web_seed_entry::http_seed);
            }
        }

        if (m_torrent_file->is_merkle_torrent())
        {
            lazy_entry const* mt = rd.dict_find_string("merkle tree");
            if (mt)
            {
                std::vector<sha1_hash> tree;
                tree.resize(m_torrent_file->merkle_tree().size());
                std::memcpy(&tree[0], mt->string_ptr()
                    , (std::min)(mt->string_length(), int(tree.size()) * 20));
                if (mt->string_length() < int(tree.size()) * 20)
                    std::memset(&tree[0] + mt->string_length() / 20, 0
                        , tree.size() - mt->string_length() / 20);
                m_torrent_file->set_merkle_tree(tree);
            }
            else
            {
                // TODO: if this is a merkle torrent and we can't
                // restore the tree, we need to wipe all the
                // bits in the have array, but not necessarily
                // we might want to do a full check to see if we have
                // all the pieces
                TORRENT_ASSERT(false);
            }
        }
    }

    void torrent::write_resume_data(entry& ret) const
    {
        using namespace libtorrent::detail; // for write_*_endpoint()
        ret["file-format"] = "libtorrent resume file";
        ret["file-version"] = 1;
        ret["libtorrent-version"] = LIBTORRENT_VERSION;

        ret["total_uploaded"] = m_total_uploaded;
        ret["total_downloaded"] = m_total_downloaded;

        ret["active_time"] = m_active_time;
        ret["finished_time"] = m_finished_time;
        ret["seeding_time"] = m_seeding_time;
        ret["last_seen_complete"] = m_last_seen_complete;

        ret["num_seeds"] = m_complete;
        ret["num_incomplete"] = m_incomplete;
        ret["num_downloaders"] = m_downloaders;

        ret["sequential_download"] = m_sequential_download;

        ret["seed_mode"] = m_seed_mode;
        ret["super_seeding"] = m_super_seeding;

        ret["added_time"] = m_added_time;
        ret["completed_time"] = m_completed_time;

        ret["last_scrape"] = m_last_scrape;
        ret["last_download"] = m_last_download;
        ret["last_upload"] = m_last_upload;

        if (!m_url.empty()) ret["url"] = m_url;
        if (!m_uuid.empty()) ret["uuid"] = m_uuid;
        if (!m_source_feed_url.empty()) ret["feed"] = m_source_feed_url;

        const sha1_hash& info_hash = torrent_file().info_hash();
        ret["info-hash"] = std::string((char*)info_hash.begin(), (char*)info_hash.end());

        if (valid_metadata())
        {
            if (m_magnet_link || (m_save_resume_flags & torrent_handle::save_info_dict))
                ret["info"] = bdecode(&torrent_file().metadata()[0]
                    , &torrent_file().metadata()[0] + torrent_file().metadata_size());
        }

        // blocks per piece
        int num_blocks_per_piece =
            static_cast<int>(torrent_file().piece_length()) / block_size();
        ret["blocks per piece"] = num_blocks_per_piece;

        if (m_torrent_file->is_merkle_torrent())
        {
            // we need to save the whole merkle hash tree
            // in order to resume
            std::string& tree_str = ret["merkle tree"].string();
            std::vector<sha1_hash> const& tree = m_torrent_file->merkle_tree();
            tree_str.resize(tree.size() * 20);
            std::memcpy(&tree_str[0], &tree[0], tree.size() * 20);
        }

        // if this torrent is a seed, we won't have a piece picker
        // and there will be no half-finished pieces.
        if (!is_seed())
        {
            const std::vector<piece_picker::downloading_piece>& q
                = m_picker->get_download_queue();

            // unfinished pieces
            ret["unfinished"] = entry::list_type();
            entry::list_type& up = ret["unfinished"].list();

            // info for each unfinished piece
            for (std::vector<piece_picker::downloading_piece>::const_iterator i
                = q.begin(); i != q.end(); ++i)
            {
                if (i->finished == 0) continue;

                entry piece_struct(entry::dictionary_t);

                // the unfinished piece's index
                piece_struct["piece"] = i->index;

                std::string bitmask;
                const int num_bitmask_bytes
                    = (std::max)(num_blocks_per_piece / 8, 1);

                for (int j = 0; j < num_bitmask_bytes; ++j)
                {
                    unsigned char v = 0;
                    int bits = (std::min)(num_blocks_per_piece - j*8, 8);
                    for (int k = 0; k < bits; ++k)
                        v |= (i->info[j*8+k].state == piece_picker::block_info::state_finished)
                        ? (1 << k) : 0;
                    bitmask.append(1, v);
                    TORRENT_ASSERT(bits == 8 || j == num_bitmask_bytes - 1);
                }
                piece_struct["bitmask"] = bitmask;
                // push the struct onto the unfinished-piece list
                up.push_back(piece_struct);
            }
        }

        // save trackers
        if (!m_trackers.empty())
        {
            entry::list_type& tr_list = ret["trackers"].list();
            tr_list.push_back(entry::list_type());
            int tier = 0;
            for (std::vector<announce_entry>::const_iterator i = m_trackers.begin()
                , end(m_trackers.end()); i != end; ++i)
            {
                // don't save trackers we can't trust
                // TODO: save the send_stats state instead
                if (i->send_stats == false) continue;
                if (i->tier == tier)
                {
                    tr_list.back().list().push_back(i->url);
                }
                else
                {
                    tr_list.push_back(entry::list_t);
                    tr_list.back().list().push_back(i->url);
                    tier = i->tier;
                }
            }
        }

        // save web seeds
        if (!m_web_seeds.empty())
        {
            entry::list_type& url_list = ret["url-list"].list();
            entry::list_type& httpseed_list = ret["httpseeds"].list();
            for (std::list<web_seed_entry>::const_iterator i = m_web_seeds.begin()
                , end(m_web_seeds.end()); i != end; ++i)
            {
                if (i->type == web_seed_entry::url_seed)
                    url_list.push_back(i->url);
                else if (i->type == web_seed_entry::http_seed)
                    httpseed_list.push_back(i->url);
            }
        }

        // write have bitmask
        // the pieces string has one byte per piece. Each
        // byte is a bitmask representing different properties
        // for the piece
        // bit 0: set if we have the piece
        // bit 1: set if we have verified the piece (in seed mode)
        entry::string_type& pieces = ret["pieces"].string();
        pieces.resize(m_torrent_file->num_pieces());
        if (is_seed())
        {
            std::memset(&pieces[0], 1, pieces.size());
        }
        else
        {
            for (int i = 0, end(pieces.size()); i < end; ++i)
                pieces[i] = m_picker->have_piece(i) ? 1 : 0;
        }

        if (m_seed_mode)
        {
            TORRENT_ASSERT(m_verified.size() == pieces.size());
            for (int i = 0, end(pieces.size()); i < end; ++i)
                pieces[i] |= m_verified[i] ? 2 : 0;
        }

        // write renamed files
        // TODO: make this more generic to not just work if files have been
        // renamed, but also if they have been merged into a single file for instance
        if (&m_torrent_file->files() != &m_torrent_file->orig_files()
            && m_torrent_file->files().num_files() == m_torrent_file->orig_files().num_files())
        {
            entry::list_type& fl = ret["mapped_files"].list();
            for (torrent_info::file_iterator i = m_torrent_file->begin_files()
                , end(m_torrent_file->end_files()); i != end; ++i)
            {
                fl.push_back(m_torrent_file->files().file_path(*i));
            }
        }

        // write local peers

        std::back_insert_iterator<entry::string_type> peers(ret["peers"].string());
        std::back_insert_iterator<entry::string_type> banned_peers(ret["banned_peers"].string());
#if TORRENT_USE_IPV6
        std::back_insert_iterator<entry::string_type> peers6(ret["peers6"].string());
        std::back_insert_iterator<entry::string_type> banned_peers6(ret["banned_peers6"].string());
#endif

        // failcount is a 5 bit value
        int max_failcount = (std::min)(settings().max_failcount, 31);

        for (policy::const_iterator i = m_policy.begin_peer()
            , end(m_policy.end_peer()); i != end; ++i)
        {
            error_code ec;
            policy::peer const* p = *i;
            address addr = p->address();
            if (p->banned)
            {
#if TORRENT_USE_IPV6
                if (addr.is_v6())
                {
                    write_address(addr, banned_peers6);
                    write_uint16(p->port, banned_peers6);
                }
                else
#endif
                {
                    write_address(addr, banned_peers);
                    write_uint16(p->port, banned_peers);
                }
                continue;
            }

            // we cannot save remote connection
            // since we don't know their listen port
            // unless they gave us their listen port
            // through the extension handshake
            // so, if the peer is not connectable (i.e. we
            // don't know its listen port) or if it has
            // been banned, don't save it.
            if (!p->connectable) continue;

            // don't save peers that don't work
            if (int(p->failcount) >= max_failcount) continue;

#if TORRENT_USE_IPV6
            if (addr.is_v6())
            {
                write_address(addr, peers6);
                write_uint16(p->port, peers6);
            }
            else
#endif
            {
                write_address(addr, peers);
                write_uint16(p->port, peers);
            }
        }

        ret["upload_rate_limit"] = upload_limit();
        ret["download_rate_limit"] = download_limit();
        ret["max_connections"] = max_connections();
        ret["max_uploads"] = max_uploads();
        ret["paused"] = is_torrent_paused();
        ret["announce_to_dht"] = m_announce_to_dht;
        ret["announce_to_trackers"] = m_announce_to_trackers;
        ret["announce_to_lsd"] = m_announce_to_lsd;
        ret["auto_managed"] = m_auto_managed;

        // write piece priorities
        entry::string_type& piece_priority = ret["piece_priority"].string();
        piece_priority.resize(m_torrent_file->num_pieces());
        if (is_seed())
        {
            std::memset(&piece_priority[0], 1, pieces.size());
        }
        else
        {
            for (int i = 0, end(piece_priority.size()); i < end; ++i)
                piece_priority[i] = m_picker->piece_priority(i);
        }

        // write file priorities
        entry::list_type& file_priority = ret["file_priority"].list();
        file_priority.clear();
        for (int i = 0, end(m_file_priority.size()); i < end; ++i)
            file_priority.push_back(m_file_priority[i]);

    }

    void torrent::get_full_peer_list(std::vector<peer_list_entry>& v) const
    {
        v.clear();
        v.reserve(m_policy.num_peers());
        for (policy::const_iterator i = m_policy.begin_peer();
            i != m_policy.end_peer(); ++i)
        {
            peer_list_entry e;
            e.ip = (*i)->ip();
            e.flags = (*i)->banned ? peer_list_entry::banned : 0;
            e.failcount = (*i)->failcount;
            e.source = (*i)->source;
            v.push_back(e);
        }
    }

    void torrent::get_peer_info(std::vector<peer_info>& v)
    {
        v.clear();
        for (peer_iterator i = begin();
            i != end(); ++i)
        {
            peer_connection* peer = *i;

            // incoming peers that haven't finished the handshake should
            // not be included in this list
            if (peer->associated_torrent().expired()) continue;

            v.push_back(peer_info());
            peer_info& p = v.back();

            peer->get_peer_info(p);
#ifndef TORRENT_DISABLE_RESOLVE_COUNTRIES
            if (resolving_countries())
                resolve_peer_country(intrusive_ptr<peer_connection>(peer));
#endif
        }
    }

    void torrent::get_download_queue(std::vector<partial_piece_info>& queue)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        queue.clear();
        std::vector<block_info>& blk = m_ses.m_block_info_storage;
        blk.clear();

        if (!valid_metadata() || is_seed()) return;
        piece_picker const& p = picker();
        std::vector<piece_picker::downloading_piece> const& q
            = p.get_download_queue();

        const int blocks_per_piece = m_picker->blocks_in_piece(0);
        blk.resize(q.size() * blocks_per_piece);

        int counter = 0;
        for (std::vector<piece_picker::downloading_piece>::const_iterator i
            = q.begin(); i != q.end(); ++i, ++counter)
        {
            partial_piece_info pi;
            pi.piece_state = (partial_piece_info::state_t)i->state;
            pi.blocks_in_piece = p.blocks_in_piece(i->index);
            pi.finished = (int)i->finished;
            pi.writing = (int)i->writing;
            pi.requested = (int)i->requested;
            pi.blocks = &blk[counter * blocks_per_piece];
            int piece_size = int(torrent_file().piece_size(i->index));
            for (int j = 0; j < pi.blocks_in_piece; ++j)
            {
                block_info& bi = pi.blocks[j];
                bi.state = i->info[j].state;
                bi.block_size = j < pi.blocks_in_piece - 1 ? block_size()
                    : piece_size - (j * block_size());
                bool complete = bi.state == block_info::writing
                    || bi.state == block_info::finished;
                if (i->info[j].peer == 0)
                {
                    bi.set_peer(tcp::endpoint());
                    bi.bytes_progress = complete ? bi.block_size : 0;
                }
                else
                {
                    policy::peer* p = static_cast<policy::peer*>(i->info[j].peer);
                    if (p->connection)
                    {
                        bi.set_peer(p->connection->remote());
                        if (bi.state == block_info::requested)
                        {
                            boost::optional<piece_block_progress> pbp
                                = p->connection->downloading_piece_progress();
                            if (pbp && pbp->piece_index == i->index && pbp->block_index == j)
                            {
                                bi.bytes_progress = pbp->bytes_downloaded;
                                TORRENT_ASSERT(bi.bytes_progress <= bi.block_size);
                            }
                            else
                            {
                                bi.bytes_progress = 0;
                            }
                        }
                        else
                        {
                            bi.bytes_progress = complete ? bi.block_size : 0;
                        }
                    }
                    else
                    {
                        bi.set_peer(p->ip());
                        bi.bytes_progress = complete ? bi.block_size : 0;
                    }
                }

                pi.blocks[j].num_peers = i->info[j].num_peers;
            }
            pi.piece_index = i->index;
            queue.push_back(pi);
        }

    }

    bool torrent::connect_to_peer(policy::peer* peerinfo, bool ignore_limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        TORRENT_ASSERT(peerinfo);
        TORRENT_ASSERT(peerinfo->connection == 0);

        peerinfo->last_connected = m_ses.session_time();
#ifdef TORRENT_DEBUG
        if (!settings().allow_multiple_connections_per_ip)
        {
            // this asserts that we don't have duplicates in the policy's peer list
            peer_iterator i_ = std::find_if(m_connections.begin(), m_connections.end()
                , boost::bind(&peer_connection::remote, _1) == peerinfo->ip());
#if TORRENT_USE_I2P
            TORRENT_ASSERT(i_ == m_connections.end()
                || (*i_)->type() != peer_connection::bittorrent_connection
                || peerinfo->is_i2p_addr);
#else
            TORRENT_ASSERT(i_ == m_connections.end()
                || (*i_)->type() != peer_connection::bittorrent_connection);
#endif
        }
#endif

        // extend connect timeout by this many seconds
        int timeout_extend = 0;

        TORRENT_ASSERT(want_more_peers() || ignore_limit);
        TORRENT_ASSERT(m_ses.num_connections() < m_ses.settings().connections_limit || ignore_limit);

        tcp::endpoint a(peerinfo->ip());
        TORRENT_ASSERT(!m_apply_ip_filter
            || (m_ses.m_ip_filter.access(peerinfo->address()) & ip_filter::blocked) == 0);

        boost::shared_ptr<socket_type> s(new socket_type(m_ses.m_io_service));

#if TORRENT_USE_I2P
        bool i2p = peerinfo->is_i2p_addr;
        if (i2p)
        {
            bool ret = instantiate_connection(m_ses.m_io_service, m_ses.i2p_proxy(), *s);
            (void)ret;
            TORRENT_ASSERT(ret);
            s->get<i2p_stream>()->set_destination(static_cast<policy::i2p_peer*>(peerinfo)->destination);
            s->get<i2p_stream>()->set_command(i2p_stream::cmd_connect);
            s->get<i2p_stream>()->set_session_id(m_ses.m_i2p_conn.session_id());
            // i2p setups are slow
            timeout_extend = 20;
        }
        else
#endif
        {
            // this is where we determine if we open a regular TCP connection
            // or a uTP connection. If the m_utp_socket_manager pointer is not passed in
            // we'll instantiate a TCP connection
            utp_socket_manager* sm = 0;

            if (m_ses.m_settings.enable_outgoing_utp
                && (!m_ses.m_settings.enable_outgoing_tcp
                    || peerinfo->supports_utp
                    || peerinfo->confirmed_supports_utp))
                sm = &m_ses.m_utp_socket_manager;

            // don't make a TCP connection if it's disabled
            if (sm == 0 && !m_ses.m_settings.enable_outgoing_tcp) return false;

            void* userdata = 0;
#ifdef TORRENT_USE_OPENSSL
            if (is_ssl_torrent())
            {
                userdata = m_ssl_ctx.get();
                // SSL handshakes are slow
                timeout_extend = 10;

                // we don't support SSL over uTP yet
                sm = 0;
            }
#endif

            bool ret = instantiate_connection(m_ses.m_io_service, m_ses.proxy(), *s, userdata, sm, true);
            (void)ret;
            TORRENT_ASSERT(ret);
        }

        m_ses.setup_socket_buffers(*s);

        boost::intrusive_ptr<peer_connection> c(new bt_peer_connection(
            m_ses, shared_from_this(), s, a, peerinfo));

#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
        c->m_in_constructor = false;
#endif

        if (settings().default_peer_upload_rate)
            c->set_upload_limit(settings().default_peer_upload_rate);
        if (settings().default_peer_download_rate)
            c->set_download_limit(settings().default_peer_download_rate);

         c->add_stat(size_type(peerinfo->prev_amount_download) << 10
            , size_type(peerinfo->prev_amount_upload) << 10);
         peerinfo->prev_amount_download = 0;
         peerinfo->prev_amount_upload = 0;

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                boost::shared_ptr<peer_plugin> pp((*i)->new_connection(c.get()));
                if (pp) c->add_extension(pp);
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

        // add the newly connected peer to this torrent's peer list
        m_connections.insert(boost::get_pointer(c));
        m_ses.m_connections.insert(c);
        m_policy.set_connection(peerinfo, c.get());
        c->start();

        int timeout = settings().peer_connect_timeout;
        if (peerinfo) timeout += 3 * peerinfo->failcount;
        timeout += timeout_extend;

        TORRENT_TRY
        {
            m_ses.m_half_open.enqueue(
                boost::bind(&peer_connection::on_connect, c, _1)
                , boost::bind(&peer_connection::on_timeout, c)
                , seconds(timeout));
        }
        TORRENT_CATCH (std::exception&)
        {
            std::set<peer_connection*>::iterator i
                = m_connections.find(boost::get_pointer(c));
            if (i != m_connections.end()) m_connections.erase(i);
            c->disconnect(errors::no_error, 1);
            return false;
        }

        if (m_share_mode)
            recalc_share_mode();

        return peerinfo->connection;
    }

    bool torrent::set_metadata(char const* metadata_buf, int metadata_size)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (m_torrent_file->is_valid()) return false;

        hasher h;
        h.update(metadata_buf, metadata_size);
        sha1_hash info_hash = h.final();

        if (info_hash != m_torrent_file->info_hash())
        {
            if (alerts().should_post<metadata_failed_alert>())
            {
                alerts().post_alert(metadata_failed_alert(get_handle()));
            }
            return false;
        }

        lazy_entry metadata;
        error_code ec;
        int ret = lazy_bdecode(metadata_buf, metadata_buf + metadata_size, metadata, ec);
        if (ret != 0 || !m_torrent_file->parse_info_section(metadata, ec, 0))
        {
            // this means the metadata is correct, since we
            // verified it against the info-hash, but we
            // failed to parse it. Pause the torrent
            if (alerts().should_post<metadata_failed_alert>())
            {
                // TODO: pass in ec along with the alert
                alerts().post_alert(metadata_failed_alert(get_handle()));
            }
            set_error(errors::invalid_swarm_metadata, "");
            pause();
            return false;
        }

        if (m_ses.m_alerts.should_post<metadata_received_alert>())
        {
            m_ses.m_alerts.post_alert(metadata_received_alert(
                get_handle()));
        }

        // this makes the resume data "paused" and
        // "auto_managed" fields be ignored. If the paused
        // field is not ignored, the invariant check will fail
        // since we will be paused but without having disconnected
        // any of the peers.
        m_override_resume_data = true;

        init();

        return true;
    }

    bool torrent::attach_peer(peer_connection* p)
    {
//		INVARIANT_CHECK;

        TORRENT_ASSERT(p != 0);
        TORRENT_ASSERT(!p->is_local());

        m_has_incoming = true;

        if (m_apply_ip_filter
            && m_ses.m_ip_filter.access(p->remote().address()) & ip_filter::blocked)
        {
            if (m_ses.m_alerts.should_post<peer_blocked_alert>())
                m_ses.m_alerts.post_alert(peer_blocked_alert(get_handle(), p->remote().address()));
            p->disconnect(errors::banned_by_ip_filter);
            return false;
        }

        if ((m_state == torrent_status::queued_for_checking
            || m_state == torrent_status::checking_files
            || m_state == torrent_status::checking_resume_data)
            && valid_metadata())
        {
            p->disconnect(errors::torrent_not_ready);
            return false;
        }

        if (m_ses.m_connections.find(p) == m_ses.m_connections.end())
        {
            p->disconnect(errors::peer_not_constructed);
            return false;
        }

        if (m_ses.is_aborted())
        {
            p->disconnect(errors::session_closing);
            return false;
        }

        if (m_connections.size() >= m_max_connections)
        {
            p->disconnect(errors::too_many_connections);
            return false;
        }

        TORRENT_TRY
        {
#ifndef TORRENT_DISABLE_EXTENSIONS
            for (extension_list_t::iterator i = m_extensions.begin()
                , end(m_extensions.end()); i != end; ++i)
            {
                boost::shared_ptr<peer_plugin> pp((*i)->new_connection(p));
                if (pp) p->add_extension(pp);
            }
#endif
            if (!m_policy.new_connection(*p, m_ses.session_time()))
            {
#if defined TORRENT_LOGGING
                (*m_ses.m_logger) << time_now_string() << " CLOSING CONNECTION "
                    << p->remote() << " policy::new_connection returned false (i.e. peer list full)\n";
#endif
                p->disconnect(errors::too_many_connections);
                return false;
            }
        }
        TORRENT_CATCH (std::exception& e)
        {
            TORRENT_DECLARE_DUMMY(std::exception, e);
            (void)e;
#if defined TORRENT_LOGGING
            (*m_ses.m_logger) << time_now_string() << " CLOSING CONNECTION "
                << p->remote() << " policy::new_connection threw: " << e.what() << "\n";
#endif
            p->disconnect(errors::no_error);
            return false;
        }
        TORRENT_ASSERT(m_connections.find(p) == m_connections.end());
        peer_iterator ci = m_connections.insert(p).first;
#ifdef TORRENT_DEBUG
        error_code ec;
        TORRENT_ASSERT(p->remote() == p->get_socket()->remote_endpoint(ec) || ec);
#endif

#if defined TORRENT_DEBUG && !defined TORRENT_DISABLE_INVARIANT_CHECKS
        m_policy.check_invariant();
#endif

        if (m_share_mode)
            recalc_share_mode();

        return true;
    }

    bool torrent::want_more_peers() const
    {
        return m_connections.size() < m_max_connections
            && !is_paused()
            && ((m_state != torrent_status::checking_files
            && m_state != torrent_status::checking_resume_data
            && m_state != torrent_status::queued_for_checking)
                || !valid_metadata())
            && m_policy.num_connect_candidates() > 0
            && !m_abort
            && (m_ses.settings().seeding_outgoing_connections
                || (m_state != torrent_status::seeding
                && m_state != torrent_status::finished));
    }

    void torrent::disconnect_all(error_code const& ec)
    {
// doesn't work with the !m_allow_peers -> m_num_peers == 0 condition
//		INVARIANT_CHECK;

        while (!m_connections.empty())
        {
            peer_connection* p = *m_connections.begin();
            TORRENT_ASSERT(p->associated_torrent().lock().get() == this);

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
            (*p->m_logger) << "*** CLOSING CONNECTION: " << ec.message() << "\n";
#endif
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
            std::size_t size = m_connections.size();
#endif
            if (p->is_disconnecting())
                m_connections.erase(m_connections.begin());
            else
                p->disconnect(ec);
            TORRENT_ASSERT(m_connections.size() <= size);
        }
    }

    // this returns true if lhs is a better disconnect candidate than rhs
    bool compare_disconnect_peer(peer_connection const* lhs, peer_connection const* rhs)
    {
        // prefer to disconnect peers that are already disconnecting
        if (lhs->is_disconnecting() != rhs->is_disconnecting())
            return lhs->is_disconnecting();

        // prefer to disconnect peers we're not interested in
        if (lhs->is_interesting() != rhs->is_interesting())
            return rhs->is_interesting();

        // prefer to disconnect peers that are not seeds
        if (lhs->is_seed() != rhs->is_seed())
            return rhs->is_seed();

        // prefer to disconnect peers that are on parole
        if (lhs->on_parole() != rhs->on_parole())
            return lhs->on_parole();

        // prefer to disconnect peers that send data at a lower rate
        size_type lhs_transferred = lhs->statistics().total_payload_download();
        size_type rhs_transferred = rhs->statistics().total_payload_download();

        ptime now = time_now();
        size_type lhs_time_connected = total_seconds(now - lhs->connected_time());
        size_type rhs_time_connected = total_seconds(now - rhs->connected_time());

        lhs_transferred /= lhs_time_connected + 1;
        rhs_transferred /= (rhs_time_connected + 1);
        if (lhs_transferred != rhs_transferred)
            return lhs_transferred < rhs_transferred;

        // prefer to disconnect peers that chokes us
        if (lhs->is_choked() != rhs->is_choked())
            return lhs->is_choked();

        return lhs->last_received() < rhs->last_received();
    }

    int torrent::disconnect_peers(int num, error_code const& ec)
    {
        INVARIANT_CHECK;

#ifdef TORRENT_DEBUG
        for (std::set<peer_connection*>::iterator i = m_connections.begin()
            , end(m_connections.end()); i != end; ++i)
        {
            // make sure this peer is not a dangling pointer
            TORRENT_ASSERT(m_ses.has_peer(*i));
        }
#endif
        int ret = 0;
        while (ret < num && !m_connections.empty())
        {
            std::set<peer_connection*>::iterator i = std::min_element(
                m_connections.begin(), m_connections.end(), compare_disconnect_peer);

            peer_connection* p = *i;
            ++ret;
            TORRENT_ASSERT(p->associated_torrent().lock().get() == this);
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
            int num_conns = m_connections.size();
#endif
            p->disconnect(ec);
            TORRENT_ASSERT(int(m_connections.size()) == num_conns - 1);
        }

        return ret;
    }

    int torrent::bandwidth_throttle(int channel) const
    {
        return m_bandwidth_channel[channel].throttle();
    }

    // called when torrent is finished (all interesting
    // pieces have been downloaded)
    void torrent::finished()
    {
        INVARIANT_CHECK;

        //std::cout << "jrr: torrent::finished (" << to_hex(info_hash().to_string()) << ")" << std::endl;

        TORRENT_ASSERT(is_finished());
        TORRENT_ASSERT(m_state != torrent_status::finished && m_state != torrent_status::seeding);

        if (alerts().should_post<torrent_finished_alert>())
        {
            alerts().post_alert(torrent_finished_alert(
                get_handle()));
        }

        set_state(torrent_status::finished);
        set_queue_position(-1);

        // we have to call completed() before we start
        // disconnecting peers, since there's an assert
        // to make sure we're cleared the piece picker
        if (is_seed()) completed();

        send_upload_only();

        m_completed_time = time(0);

        // disconnect all seeds
        // TODO: should disconnect all peers that have the pieces we have
        // not just seeds
        std::vector<peer_connection*> seeds;
        for (peer_iterator i = m_connections.begin();
            i != m_connections.end(); ++i)
        {
            peer_connection* p = *i;
            TORRENT_ASSERT(p->associated_torrent().lock().get() == this);
            if (p->upload_only())
            {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
                (*p->m_logger) << "*** SEED, CLOSING CONNECTION\n";
#endif
                seeds.push_back(p);
            }
        }
        std::for_each(seeds.begin(), seeds.end()
            , boost::bind(&peer_connection::disconnect, _1, errors::torrent_finished, 0));

        if (m_abort) return;

        m_policy.recalculate_connect_candidates();

        TORRENT_ASSERT(m_storage);
        // we need to keep the object alive during this operation
        m_storage->async_release_files(
            boost::bind(&torrent::on_files_released, shared_from_this(), _1, _2));

        // this torrent just completed downloads, which means it will fall
        // under a different limit with the auto-manager. Make sure we
        // update auto-manage torrents in that case
        if (m_auto_managed && m_ses.m_auto_manage_time_scaler > 1)
            m_ses.m_auto_manage_time_scaler = 1;
    }

    // this is called when we were finished, but some files were
    // marked for downloading, and we are no longer finished
    void torrent::resume_download()
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(!is_finished());
        set_state(torrent_status::downloading);
        set_queue_position((std::numeric_limits<int>::max)());
        m_policy.recalculate_connect_candidates();

        m_completed_time = 0;

        send_upload_only();
    }

    // called when torrent is complete (all pieces downloaded)
    void torrent::completed()
    {
        m_picker.reset();

        set_state(torrent_status::seeding);
        if (!m_announcing) return;

        ptime now = time_now();
        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
        {
            if (i->complete_sent) continue;
            i->next_announce = now;
            i->min_announce = now;
        }
        announce_with_tracker();
    }

    // this will move the tracker with the given index
    // to a prioritized position in the list (move it towards
    // the begining) and return the new index to the tracker.
    int torrent::prioritize_tracker(int index)
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < int(m_trackers.size()));
        if (index >= (int)m_trackers.size()) return -1;

        while (index > 0 && m_trackers[index].tier == m_trackers[index-1].tier)
        {
            using std::swap;
            swap(m_trackers[index], m_trackers[index-1]);
            if (m_last_working_tracker == index) --m_last_working_tracker;
            else if (m_last_working_tracker == index - 1) ++m_last_working_tracker;
            --index;
        }
        return index;
    }

    int torrent::deprioritize_tracker(int index)
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < int(m_trackers.size()));
        if (index >= (int)m_trackers.size()) return -1;

        while (index < int(m_trackers.size()) - 1 && m_trackers[index].tier == m_trackers[index + 1].tier)
        {
            using std::swap;
            swap(m_trackers[index], m_trackers[index + 1]);
            if (m_last_working_tracker == index) ++m_last_working_tracker;
            else if (m_last_working_tracker == index + 1) --m_last_working_tracker;
            ++index;
        }
        return index;
    }

    void torrent::files_checked()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(m_torrent_file->is_valid());

        if (m_abort) return;

        // we might be finished already, in which case we should
        // not switch to downloading mode. If all files are
        // filtered, we're finished when we start.
        if (m_state != torrent_status::finished)
            set_state(torrent_status::downloading);

        INVARIANT_CHECK;

        if (m_ses.m_alerts.should_post<torrent_checked_alert>())
        {
            m_ses.m_alerts.post_alert(torrent_checked_alert(
                get_handle()));
        }

        // calling pause will also trigger the auto managed
        // recalculation
        if (m_auto_managed) pause();

        // if this is an auto managed torrent, force a recalculation
        // of which torrents to have active
        if (m_auto_managed && m_ses.m_auto_manage_time_scaler > 1)
            m_ses.m_auto_manage_time_scaler = 1;

        if (!is_seed())
        {
            // turn off super seeding if we're not a seed
            if (m_super_seeding) m_super_seeding = false;

            // if we just finished checking and we're not a seed, we are
            // likely to be unpaused
            if (m_ses.m_auto_manage_time_scaler > 1)
                m_ses.m_auto_manage_time_scaler = 1;

            if (is_finished() && m_state != torrent_status::finished)
                finished();
        }
        else
        {
            for (std::vector<announce_entry>::iterator i = m_trackers.begin()
                , end(m_trackers.end()); i != end; ++i)
                i->complete_sent = true;

            if (m_state != torrent_status::finished)
                finished();
        }

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                (*i)->on_files_checked();
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

        if (!m_connections_initialized)
        {
            m_connections_initialized = true;
            // all peer connections have to initialize themselves now that the metadata
            // is available
            for (torrent::peer_iterator i = m_connections.begin();
                i != m_connections.end();)
            {
                peer_connection* pc = *i;
                ++i;
                if (pc->is_disconnecting()) continue;
                pc->on_metadata_impl();
                if (pc->is_disconnecting()) continue;
                pc->init();
            }
        }

        m_files_checked = true;

        start_announcing();
    }

    alert_manager& torrent::alerts() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        return m_ses.m_alerts;
    }

    std::string torrent::save_path() const
    {
        return m_save_path;
    }

    bool torrent::rename_file(int index, std::string const& name)
    {
        INVARIANT_CHECK;

        TORRENT_ASSERT(index >= 0);
        TORRENT_ASSERT(index < m_torrent_file->num_files());

        if (!m_owning_storage.get()) return false;

        m_owning_storage->async_rename_file(index, name
            , boost::bind(&torrent::on_file_renamed, shared_from_this(), _1, _2));
        return true;
    }

    void torrent::move_storage(std::string const& save_path)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (m_owning_storage.get())
        {
            m_owning_storage->async_move_storage(save_path
                , boost::bind(&torrent::on_storage_moved, shared_from_this(), _1, _2));
        }
        else
        {
            m_save_path = save_path;
            if (alerts().should_post<storage_moved_alert>())
            {
                alerts().post_alert(storage_moved_alert(get_handle(), m_save_path));
            }
        }
    }

    void torrent::on_storage_moved(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (ret == 0)
        {
            if (alerts().should_post<storage_moved_alert>())
            {
                alerts().post_alert(storage_moved_alert(get_handle(), j.str));
            }
            m_save_path = j.str;
        }
        else
        {
            if (alerts().should_post<storage_moved_failed_alert>())
            {
                alerts().post_alert(storage_moved_failed_alert(get_handle(), j.error));
            }
        }
    }

    piece_manager& torrent::filesystem()
    {
        TORRENT_ASSERT(m_owning_storage.get());
        TORRENT_ASSERT(m_storage);
        return *m_storage;
    }


    torrent_handle torrent::get_handle()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        return torrent_handle(shared_from_this());
    }

    session_settings const& torrent::settings() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        return m_ses.settings();
    }

#ifdef TORRENT_DEBUG
    void torrent::check_invariant() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (is_paused()) TORRENT_ASSERT(num_peers() == 0 || m_graceful_pause_mode);

        if (!should_check_files())
            TORRENT_ASSERT(m_state != torrent_status::checking_files);
        else
            TORRENT_ASSERT(m_queued_for_checking);

        if (!m_ses.m_queued_for_checking.empty())
        {
            // if there are torrents waiting to be checked
            // assert that there's a torrent that is being
            // processed right now
            int found = 0;
            int found_active = 0;
            for (aux::session_impl::torrent_map::iterator i = m_ses.m_torrents.begin()
                , end(m_ses.m_torrents.end()); i != end; ++i)
                if (i->second->m_state == torrent_status::checking_files)
                {
                    ++found;
                    if (i->second->should_check_files()) ++found_active;
                }

            // if the session is paused, there might still be some torrents
            // in the checking_files state that haven't been dequeued yet
            if (m_ses.is_paused())
            {
                TORRENT_ASSERT(found_active == 0);
            }
            else
            {
                // the case of 2 is in the special case where one switches over from
                // checking to complete.
                TORRENT_ASSERT(found_active >= 1);
                TORRENT_ASSERT(found_active <= 2);
                TORRENT_ASSERT(found >= 1);
            }
        }

        TORRENT_ASSERT(m_resume_entry.type() == lazy_entry::dict_t
            || m_resume_entry.type() == lazy_entry::none_t);

        int num_uploads = 0;
        std::map<piece_block, int> num_requests;
        for (const_peer_iterator i = begin(); i != end(); ++i)
        {
#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
            // make sure this peer is not a dangling pointer
            TORRENT_ASSERT(m_ses.has_peer(*i));
#endif
            peer_connection const& p = *(*i);
            for (std::vector<pending_block>::const_iterator i = p.request_queue().begin()
                , end(p.request_queue().end()); i != end; ++i)
                ++num_requests[i->block];
            for (std::vector<pending_block>::const_iterator i = p.download_queue().begin()
                , end(p.download_queue().end()); i != end; ++i)
                if (!i->not_wanted && !i->timed_out) ++num_requests[i->block];
            if (!p.is_choked() && !p.ignore_unchoke_slots()) ++num_uploads;
            torrent* associated_torrent = p.associated_torrent().lock().get();
            if (associated_torrent != this && associated_torrent != 0)
                TORRENT_ASSERT(false);
        }
        TORRENT_ASSERT(num_uploads == int(m_num_uploads));

        if (has_picker())
        {
            for (std::map<piece_block, int>::iterator i = num_requests.begin()
                , end(num_requests.end()); i != end; ++i)
            {
                piece_block b = i->first;
                int count = i->second;
                int picker_count = m_picker->num_peers(b);
                if (!m_picker->is_downloaded(b))
                    TORRENT_ASSERT(picker_count == count);
            }
            TORRENT_ASSERT(num_have() >= m_picker->num_have_filtered());
        }

        if (valid_metadata())
        {
            TORRENT_ASSERT(m_abort || m_error || !m_picker || m_picker->num_pieces() == m_torrent_file->num_pieces());
        }
        else
        {
            TORRENT_ASSERT(m_abort || m_error || !m_picker || m_picker->num_pieces() == 0);
        }

#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
        // make sure we haven't modified the peer object
        // in a way that breaks the sort order
        if (m_policy.begin_peer() != m_policy.end_peer())
        {
            policy::const_iterator i = m_policy.begin_peer();
            policy::const_iterator prev = i++;
            policy::const_iterator end(m_policy.end_peer());
            policy::peer_address_compare cmp;
            for (; i != end; ++i, ++prev)
            {
                TORRENT_ASSERT(!cmp(*i, *prev));
            }
        }
#endif

        size_type total_done = quantized_bytes_done();
        if (m_torrent_file->is_valid())
        {
            if (is_seed())
                TORRENT_ASSERT(total_done == m_torrent_file->total_size());
            else
                TORRENT_ASSERT(total_done != m_torrent_file->total_size() || !m_files_checked);

            TORRENT_ASSERT(block_size() <= m_torrent_file->piece_length());
        }
        else
        {
            TORRENT_ASSERT(total_done == 0);
        }

        if (m_picker && !m_abort)
        {
            // make sure that pieces that have completed the download
            // of all their blocks are in the disk io thread's queue
            // to be checked.
            const std::vector<piece_picker::downloading_piece>& dl_queue
                = m_picker->get_download_queue();
            for (std::vector<piece_picker::downloading_piece>::const_iterator i =
                dl_queue.begin(); i != dl_queue.end(); ++i)
            {
                const int blocks_per_piece = m_picker->blocks_in_piece(i->index);

                bool complete = true;
                for (int j = 0; j < blocks_per_piece; ++j)
                {
                    if (i->info[j].state == piece_picker::block_info::state_finished)
                        continue;
                    complete = false;
                    break;
                }
            }
        }

        if (m_files_checked && valid_metadata())
        {
            TORRENT_ASSERT(block_size() > 0);
        }
//		if (is_seed()) TORRENT_ASSERT(m_picker.get() == 0);


        for (std::vector<size_type>::const_iterator i = m_file_progress.begin()
            , end(m_file_progress.end()); i != end; ++i)
        {
            int index = i - m_file_progress.begin();
            TORRENT_ASSERT(*i <= m_torrent_file->files().at(index).size);
        }
    }
#endif

    void torrent::set_sequential_download(bool sd)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        m_sequential_download = sd;
    }

    void torrent::queue_up()
    {
        set_queue_position(queue_position() == 0
            ? queue_position() : queue_position() - 1);
    }

    void torrent::queue_down()
    {
        set_queue_position(queue_position() + 1);
    }

    void torrent::set_queue_position(int p)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT((p == -1) == is_finished()
            || (!m_auto_managed && p == -1)
            || (m_abort && p == -1));
        if (is_finished() && p != -1) return;
        if (p == m_sequence_number) return;

        session_impl::torrent_map& torrents = m_ses.m_torrents;
        if (p >= 0 && m_sequence_number == -1)
        {
            int max_seq = -1;
            for (session_impl::torrent_map::iterator i = torrents.begin()
                , end(torrents.end()); i != end; ++i)
            {
                torrent* t = i->second.get();
                if (t->m_sequence_number > max_seq) max_seq = t->m_sequence_number;
            }
            m_sequence_number = (std::min)(max_seq + 1, p);
        }
        else if (p < 0)
        {
            for (session_impl::torrent_map::iterator i = torrents.begin()
                , end(torrents.end()); i != end; ++i)
            {
                torrent* t = i->second.get();
                if (t == this) continue;
                if (t->m_sequence_number >= m_sequence_number
                    && t->m_sequence_number != -1)
                    --t->m_sequence_number;
            }
            m_sequence_number = p;
        }
        else if (p < m_sequence_number)
        {
            for (session_impl::torrent_map::iterator i = torrents.begin()
                , end(torrents.end()); i != end; ++i)
            {
                torrent* t = i->second.get();
                if (t == this) continue;
                if (t->m_sequence_number >= p
                    && t->m_sequence_number < m_sequence_number
                    && t->m_sequence_number != -1)
                    ++t->m_sequence_number;
            }
            m_sequence_number = p;
        }
        else if (p > m_sequence_number)
        {
            int max_seq = 0;
            for (session_impl::torrent_map::iterator i = torrents.begin()
                , end(torrents.end()); i != end; ++i)
            {
                torrent* t = i->second.get();
                int pos = t->m_sequence_number;
                if (pos > max_seq) max_seq = pos;
                if (t == this) continue;

                if (pos <= p
                        && pos > m_sequence_number
                        && pos != -1)
                    --t->m_sequence_number;

            }
            m_sequence_number = (std::min)(max_seq, p);
        }

        if (m_ses.m_auto_manage_time_scaler > 2)
            m_ses.m_auto_manage_time_scaler = 2;
    }

    void torrent::set_max_uploads(int limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(limit >= -1);
        if (limit <= 0) limit = (std::numeric_limits<int>::max)();
        m_max_uploads = limit;
    }

    void torrent::set_max_connections(int limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(limit >= -1);
        if (limit <= 0) limit = (std::numeric_limits<int>::max)();
        m_max_connections = limit;

        if (num_peers() > int(m_max_connections))
        {
            disconnect_peers(num_peers() - m_max_connections
                , error_code(errors::too_many_connections, get_libtorrent_category()));
        }
    }

    int torrent::get_peer_upload_limit(tcp::endpoint ip) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        const_peer_iterator i = std::find_if(m_connections.begin(), m_connections.end()
            , boost::bind(&peer_connection::remote, _1) == ip);
        if (i == m_connections.end()) return -1;
        return (*i)->get_upload_limit();
    }

    int torrent::get_peer_download_limit(tcp::endpoint ip) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        const_peer_iterator i = std::find_if(m_connections.begin(), m_connections.end()
            , boost::bind(&peer_connection::remote, _1) == ip);
        if (i == m_connections.end()) return -1;
        return (*i)->get_download_limit();
    }

    void torrent::set_peer_upload_limit(tcp::endpoint ip, int limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(limit >= -1);
        peer_iterator i = std::find_if(m_connections.begin(), m_connections.end()
            , boost::bind(&peer_connection::remote, _1) == ip);
        if (i == m_connections.end()) return;
        (*i)->set_upload_limit(limit);
    }

    void torrent::set_peer_download_limit(tcp::endpoint ip, int limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(limit >= -1);
        peer_iterator i = std::find_if(m_connections.begin(), m_connections.end()
            , boost::bind(&peer_connection::remote, _1) == ip);
        if (i == m_connections.end()) return;
        (*i)->set_download_limit(limit);
    }

    void torrent::set_upload_limit(int limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(limit >= -1);
        if (limit <= 0) limit = 0;
        m_bandwidth_channel[peer_connection::upload_channel].throttle(limit);
    }

    int torrent::upload_limit() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        int limit = m_bandwidth_channel[peer_connection::upload_channel].throttle();
        if (limit == (std::numeric_limits<int>::max)()) limit = -1;
        return limit;
    }

    void torrent::set_download_limit(int limit)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(limit >= -1);
        if (limit <= 0) limit = 0;
        m_bandwidth_channel[peer_connection::download_channel].throttle(limit);
    }

    int torrent::download_limit() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        int limit = m_bandwidth_channel[peer_connection::download_channel].throttle();
        if (limit == (std::numeric_limits<int>::max)()) limit = -1;
        return limit;
    }

    void torrent::delete_files()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING || defined TORRENT_LOGGING
        log_to_all_peers("DELETING FILES IN TORRENT");
#endif

        disconnect_all(errors::torrent_removed);
        stop_announcing();

        if (m_owning_storage.get())
        {
            TORRENT_ASSERT(m_storage);
            m_storage->async_delete_files(
                boost::bind(&torrent::on_files_deleted, shared_from_this(), _1, _2));
        }
    }

    void torrent::clear_error()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!m_error) return;
        bool checking_files = should_check_files();
        if (m_ses.m_auto_manage_time_scaler > 2)
            m_ses.m_auto_manage_time_scaler = 2;
        m_error = error_code();
        m_error_file.clear();

        // if we haven't downloaded the metadata from m_url, try again
        if (!m_url.empty() && !m_torrent_file->is_valid())
        {
            start_download_url();
            return;
        }
        // if the error happened during initialization, try again now
        if (!m_storage) init();
        if (!checking_files && should_check_files())
            queue_torrent_check();

    }

    void torrent::set_error(error_code const& ec, std::string const& error_file)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        bool checking_files = should_check_files();
        m_error = ec;
        m_error_file = error_file;

        if (alerts().should_post<torrent_error_alert>())
            alerts().post_alert(torrent_error_alert(get_handle(), ec));

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING || defined TORRENT_LOGGING
        if (ec)
        {
            char buf[1024];
            snprintf(buf, sizeof(buf), "TORRENT ERROR: %s: %s", ec.message().c_str(), error_file.c_str());
            log_to_all_peers(buf);
        }
#endif

        if (checking_files && !should_check_files())
        {
            // stop checking
            m_storage->abort_disk_io();
            dequeue_torrent_check();
            set_state(torrent_status::queued_for_checking);
        }
    }

    void torrent::auto_managed(bool a)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (m_auto_managed == a) return;
        bool checking_files = should_check_files();
        m_auto_managed = a;

        // we need to save this new state as well
        m_need_save_resume_data = true;

        // recalculate which torrents should be
        // paused
        m_ses.m_auto_manage_time_scaler = 0;

        if (!checking_files && should_check_files())
        {
            queue_torrent_check();
        }
        else if (checking_files && !should_check_files())
        {
            // stop checking
            m_storage->abort_disk_io();
            dequeue_torrent_check();
            set_state(torrent_status::queued_for_checking);
        }

        // if this torrent is running and just became auto-managed
        // we might want to pause it in favor of some other torrent
        if (m_auto_managed && !is_paused()
            && m_ses.m_auto_manage_time_scaler > 1)
            m_ses.m_auto_manage_time_scaler = 1;
    }

    // the higher seed rank, the more important to seed
    int torrent::seed_rank(session_settings const& s) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        enum flags
        {
            seed_ratio_not_met = 0x400000,
            recently_started = 0x200000,
            no_seeds = 0x100000,
            prio_mask = 0xfffff
        };

        if (!is_finished()) return 0;

        int scale = 100;
        if (!is_seed()) scale = 50;

        int ret = 0;

        ptime now = time_now();

        int finished_time = m_finished_time;
        int download_time = int(m_active_time) - finished_time;

        // if we haven't yet met the seed limits, set the seed_ratio_not_met
        // flag. That will make this seed prioritized
        // downloaded may be 0 if the torrent is 0-sized
        size_type downloaded = (std::max)(m_total_downloaded, m_torrent_file->total_size());
        if (finished_time < s.seed_time_limit
            && (download_time > 1 && finished_time / download_time < s.seed_time_ratio_limit)
            && downloaded > 0
            && m_total_uploaded / downloaded < s.share_ratio_limit)
            ret |= seed_ratio_not_met;

        // if this torrent is running, and it was started less
        // than 30 minutes ago, give it priority, to avoid oscillation
        if (!is_paused() && now - m_started < minutes(30))
            ret |= recently_started;

        // if we have any scrape data, use it to calculate
        // seed rank
        int seeds = 0;
        int downloaders = 0;

        if (m_complete != 0xffffff) seeds = m_complete;
        else seeds = m_policy.num_seeds();

        if (m_downloaders != 0xffffff) downloaders = m_downloaders;
        else if (m_incomplete != 0xffffff) downloaders = m_incomplete;
        else downloaders = m_policy.num_peers() - m_policy.num_seeds();

        if (seeds == 0)
        {
            ret |= no_seeds;
            ret |= downloaders & prio_mask;
        }
        else
        {
            ret |= (downloaders * scale / seeds) & prio_mask;
        }

        return ret;
    }

    // this is an async operation triggered by the client
    void torrent::save_resume_data(int flags)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (!valid_metadata())
        {
            alerts().post_alert(save_resume_data_failed_alert(get_handle()
                , errors::no_metadata));
            return;
        }

        if (!m_owning_storage.get())
        {
            alerts().post_alert(save_resume_data_failed_alert(get_handle()
                , errors::destructing_torrent));
            return;
        }

        m_need_save_resume_data = false;
        m_last_saved_resume = time(0);
        m_save_resume_flags = boost::uint8_t(flags);

        TORRENT_ASSERT(m_storage);
        if (m_state == torrent_status::queued_for_checking
            || m_state == torrent_status::checking_files
            || m_state == torrent_status::checking_resume_data)
        {
            boost::shared_ptr<entry> rd(new entry);
            write_resume_data(*rd);
            alerts().post_alert(save_resume_data_alert(rd
                , get_handle()));
            return;
        }

        if (flags & torrent_handle::flush_disk_cache)
            m_storage->async_release_files();

        m_storage->async_save_resume_data(
            boost::bind(&torrent::on_save_resume_data, shared_from_this(), _1, _2));
    }

    bool torrent::should_check_files() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        // #error should m_allow_peers really affect checking?
        return (m_state == torrent_status::checking_files
            || m_state == torrent_status::queued_for_checking)
            && (m_allow_peers || m_auto_managed)
            && !has_error()
            && !m_abort
            && !m_graceful_pause_mode
            && !m_ses.is_paused();
    }

    void torrent::flush_cache()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        m_storage->async_release_files(
            boost::bind(&torrent::on_cache_flushed, shared_from_this(), _1, _2));
    }

    void torrent::on_cache_flushed(int ret, disk_io_job const& j)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (m_ses.is_aborted()) return;

        if (alerts().should_post<cache_flushed_alert>())
            alerts().post_alert(cache_flushed_alert(get_handle()));
    }

    bool torrent::is_paused() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        return !m_allow_peers || m_ses.is_paused() || m_graceful_pause_mode;
    }

    void torrent::pause(bool graceful)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (!m_allow_peers) return;
        if (!graceful) m_allow_peers = false;
        m_announce_to_dht = false;
        m_announce_to_trackers = false;
        m_announce_to_lsd = false;

        // we need to save this new state
        m_need_save_resume_data = true;

        bool prev_graceful = m_graceful_pause_mode;
        m_graceful_pause_mode = graceful;

        if (!m_ses.is_paused() || (prev_graceful && !m_graceful_pause_mode))
            do_pause();
    }

    void torrent::do_pause()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!is_paused()) return;

#ifdef TORRENT_USE_OPENSSL
        if (m_torrent_file->is_valid() && m_torrent_file->encryption_key().size() == 32 && m_in_encrypted_list)
        {
            m_ses.m_encrypted_torrents.erase(shared_from_this());
            m_in_encrypted_list = false;
        }
#endif

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                if ((*i)->on_pause()) return;
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING || defined TORRENT_LOGGING
        log_to_all_peers("PAUSING TORRENT");
#endif

        // this will make the storage close all
        // files and flush all cached data
        if (m_owning_storage.get())
        {
            TORRENT_ASSERT(m_storage);
            m_storage->async_release_files(
                boost::bind(&torrent::on_torrent_paused, shared_from_this(), _1, _2));
            m_storage->async_clear_read_cache();
        }
        else
        {
            if (alerts().should_post<torrent_paused_alert>())
                alerts().post_alert(torrent_paused_alert(get_handle()));
        }

        if (!m_graceful_pause_mode)
        {
            disconnect_all(errors::torrent_paused);
        }
        else
        {
            // disconnect all peers with no outstanding data to receive
            // and choke all remaining peers to prevent responding to new
            // requests
            for (std::set<peer_connection*>::iterator i = m_connections.begin()
                , end(m_connections.end()); i != end;)
            {
                std::set<peer_connection*>::iterator j = i++;
                peer_connection* p = *j;
                TORRENT_ASSERT(p->associated_torrent().lock().get() == this);

                if (p->is_disconnecting())
                    m_connections.erase(j);

                if (p->outstanding_bytes() > 0)
                {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
                    p->peer_log("*** CHOKING PEER: torrent graceful paused");
#endif
                    // remove any un-sent requests from the queue
                    p->clear_request_queue();
                    // don't accept new requests from the peer
                    if (!p->is_choked()) m_ses.choke_peer(*p);
                    continue;
                }

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
                p->peer_log("*** CLOSING CONNECTION: torrent_paused");
#endif
                p->disconnect(errors::torrent_paused);
            }
        }

        stop_announcing();

        if (m_queued_for_checking && !should_check_files())
        {
            // stop checking
            m_storage->abort_disk_io();
            dequeue_torrent_check();
            set_state(torrent_status::queued_for_checking);
            TORRENT_ASSERT(!m_queued_for_checking);
        }

        // if this torrent was just paused
        // we might have to resume some other auto-managed torrent
        if (m_ses.m_auto_manage_time_scaler > 1)
            m_ses.m_auto_manage_time_scaler = 1;
    }

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING || defined TORRENT_LOGGING
    void torrent::log_to_all_peers(char const* message)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
        for (peer_iterator i = m_connections.begin();
                i != m_connections.end(); ++i)
        {
            (*i)->peer_log("*** %s", message);
        }
#endif

        (*m_ses.m_logger) << time_now_string() << " " << message << "\n";
    }
#endif

    void torrent::set_allow_peers(bool b, bool graceful)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        if (m_allow_peers == b
            && m_graceful_pause_mode == graceful) return;

        m_allow_peers = b;
        if (!m_ses.is_paused())
            m_graceful_pause_mode = graceful;

        if (!b)
        {
            m_announce_to_dht = false;
            m_announce_to_trackers = false;
            m_announce_to_lsd = false;
            do_pause();
        }
        else
        {
            do_resume();
        }
    }

    void torrent::resume()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        if (m_allow_peers
            && m_announce_to_dht
            && m_announce_to_trackers
            && m_announce_to_lsd) return;
        m_allow_peers = true;
        m_announce_to_dht = true;
        m_announce_to_trackers = true;
        m_announce_to_lsd = true;
        if (!m_ses.is_paused()) m_graceful_pause_mode = false;

        // we need to save this new state
        m_need_save_resume_data = true;

        do_resume();
    }

    void torrent::do_resume()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (is_paused()) return;

#ifdef TORRENT_USE_OPENSSL
        if (m_torrent_file->is_valid() && m_torrent_file->encryption_key().size() == 32 && !m_in_encrypted_list)
        {
            m_ses.m_encrypted_torrents.insert(shared_from_this());
            m_in_encrypted_list = true;
        }
#endif

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                if ((*i)->on_resume()) return;
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

        if (alerts().should_post<torrent_resumed_alert>())
            alerts().post_alert(torrent_resumed_alert(get_handle()));

        m_started = time_now();
        clear_error();
        start_announcing();
        if (!m_queued_for_checking && should_check_files())
            queue_torrent_check();
    }

    void torrent::update_tracker_timer(ptime now)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!m_announcing)
        {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
            debug_log("*** update tracker timer: not announcing");
#endif
            return;
        }

        ptime next_announce = max_time();
        int tier = INT_MAX;

        bool found_working = false;

        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
        {
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
            char msg[1000];
            snprintf(msg, sizeof(msg), "*** update tracker timer: considering \"%s\" "
                "[ announce_to_all_tiers: %d announce_to_all_trackers: %d"
                " found_working: %d i->tier: %d tier: %d "
                " is_working: %d fails: %d fail_limit: %d updating: %d ]"
                , i->url.c_str(), settings().announce_to_all_tiers
                , settings().announce_to_all_trackers, found_working
                , i->tier, tier, i->is_working(), i->fails, i->fail_limit
                , i->updating);
            debug_log(msg);
#endif
            if (settings().announce_to_all_tiers
                && found_working
                && i->tier <= tier
                && tier != INT_MAX)
                continue;

            if (i->tier > tier && !settings().announce_to_all_tiers) break;
            if (i->is_working()) { tier = i->tier; found_working = false; }
            if (i->fails >= i->fail_limit && i->fail_limit != 0) continue;
            if (i->updating)
            {
                found_working = true;
            }
            else
            {
                ptime next_tracker_announce = (std::max)(i->next_announce, i->min_announce);
                if (next_tracker_announce < next_announce
                    && (!found_working || i->is_working()))
                    next_announce = next_tracker_announce;
            }
            if (i->is_working()) found_working = true;
            if (found_working
                && !settings().announce_to_all_trackers
                && !settings().announce_to_all_tiers) break;
        }

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
        char msg[200];
        snprintf(msg, sizeof(msg), "*** update tracker timer: next_announce < now %d"
            " m_waiting_tracker: %d next_announce_in: %d"
            , next_announce <= now, m_waiting_tracker, total_seconds(now - next_announce));
        debug_log(msg);
#endif
        if (next_announce <= now) next_announce = now;

        m_waiting_tracker = true;
        error_code ec;
        boost::weak_ptr<torrent> self(shared_from_this());

        // don't re-issue the timer if it's the same expiration time as last time
        if (m_tracker_timer.expires_at() == next_announce) return;

#if defined TORRENT_ASIO_DEBUGGING
        add_outstanding_async("tracker::on_tracker_announce_disp");
#endif
        m_tracker_timer.expires_at(next_announce, ec);
        m_tracker_timer.async_wait(boost::bind(&torrent::on_tracker_announce_disp, self, _1));
    }

    void torrent::start_announcing()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (is_paused()) return;
        // if we don't have metadata, we need to announce
        // before checking files, to get peers to
        // request the metadata from
        if (!m_files_checked && valid_metadata()) return;
        if (m_announcing) return;

        m_announcing = true;

        if (!m_trackers.empty())
        {
            // tell the tracker that we're back
            std::for_each(m_trackers.begin(), m_trackers.end()
                , boost::bind(&announce_entry::reset, _1));
        }

        // reset the stats, since from the tracker's
        // point of view, this is a new session
        m_total_failed_bytes = 0;
        m_total_redundant_bytes = 0;
        m_stat.clear();

        announce_with_tracker();

        // private torrents are never announced on LSD
        // or on DHT, we don't need this timer.
        if (!m_torrent_file->is_valid()
            || (!m_torrent_file->priv()
                && (!m_torrent_file->is_i2p()
                    || settings().allow_i2p_mixed)))
        {
            if (m_ses.m_lsd) lsd_announce();

#ifndef TORRENT_DISABLE_DHT
            if (m_ses.m_dht) dht_announce();
#endif
        }
    }

    void torrent::stop_announcing()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!m_announcing) return;

        error_code ec;
        m_tracker_timer.cancel(ec);

        m_announcing = false;

        ptime now = time_now();
        for (std::vector<announce_entry>::iterator i = m_trackers.begin()
            , end(m_trackers.end()); i != end; ++i)
        {
            i->next_announce = now;
            i->min_announce = now;
        }
        announce_with_tracker(tracker_request::stopped);
    }

    void torrent::second_tick(stat& accumulator, int tick_interval_ms)
    {
        //std::cout << "jrr: torrent::second_tick (" << to_hex(info_hash().to_string()) << ")" << std::endl;

        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        ptime now = time_now();

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                (*i)->tick();
            } TORRENT_CATCH (std::exception&) {}
        }
#endif

        m_time_scaler--;
        if (m_time_scaler <= 0)
        {
            m_time_scaler = 10;

            if (settings().max_sparse_regions > 0
                && m_picker
                && m_picker->sparse_regions() > settings().max_sparse_regions)
            {
                // we have too many sparse regions. Prioritize pieces
                // that won't introduce new sparse regions
                // prioritize pieces that will reduce the number of sparse
                // regions even higher
                int start = m_picker->cursor();
                int end = m_picker->reverse_cursor();
                for (int i = start; i < end; ++i)
                    update_sparse_piece_prio(i, start, end);
            }

            // ------------------------
            // upload shift
            // ------------------------

            // this part will shift downloads
            // from peers that are seeds and peers
            // that don't want to download from us
            // to peers that cannot upload anything
            // to us. The shifting will make sure
            // that the torrent's share ratio
            // will be maintained

            // if the share ratio is 0 (infinite)
            // m_available_free_upload isn't used
            // because it isn't necessary
            if (ratio() != 0.f)
            {
                // accumulate all the free download we get
                // and add it to the available free upload
                add_free_upload(collect_free_download(
                    this->begin(), this->end()));

                // distribute the free upload among the peers
                m_available_free_upload = distribute_free_upload(
                    this->begin(), this->end(), m_available_free_upload);
            }

            m_policy.pulse();
        }

        // if we're in upload only mode and we're auto-managed
        // leave upload mode every 10 minutes hoping that the error
        // condition has been fixed
        if (m_upload_mode && m_auto_managed && int(m_upload_mode_time)
            >= settings().optimistic_disk_retry)
        {
            set_upload_mode(false);
        }

        if (is_paused())
        {
            // let the stats fade out to 0
            accumulator += m_stat;
             m_stat.second_tick(tick_interval_ms);
            return;
        }

        if (settings().rate_limit_ip_overhead)
        {
            int up_limit = m_bandwidth_channel[peer_connection::upload_channel].throttle();
            int down_limit = m_bandwidth_channel[peer_connection::download_channel].throttle();

            if (down_limit > 0
                && m_stat.download_ip_overhead() >= down_limit
                && alerts().should_post<performance_alert>())
            {
                alerts().post_alert(performance_alert(get_handle()
                    , performance_alert::download_limit_too_low));
            }

            if (up_limit > 0
                && m_stat.upload_ip_overhead() >= up_limit
                && alerts().should_post<performance_alert>())
            {
                alerts().post_alert(performance_alert(get_handle()
                    , performance_alert::upload_limit_too_low));
            }
        }

        int seconds_since_last_tick = 1;
        if (m_ses.m_tick_residual >= 1000) ++seconds_since_last_tick;

        if (is_seed()) m_seeding_time += seconds_since_last_tick;
        if (is_finished()) m_finished_time += seconds_since_last_tick;
        if (m_upload_mode) m_upload_mode_time += seconds_since_last_tick;
        m_last_scrape += seconds_since_last_tick;
        m_active_time += seconds_since_last_tick;
        m_last_download += seconds_since_last_tick;
        m_last_upload += seconds_since_last_tick;

        // ---- TIME CRITICAL PIECES ----

        if (!m_time_critical_pieces.empty())
        {
            request_time_critical_pieces();
        }

        // ---- WEB SEEDS ----

        // if we have everything we want we don't need to connect to any web-seed
        if (!is_finished() && !m_web_seeds.empty() && m_files_checked
            && int(m_connections.size()) < m_max_connections
            && m_ses.num_connections() < m_ses.settings().connections_limit)
        {
            // keep trying web-seeds if there are any
            // first find out which web seeds we are connected to
            for (std::list<web_seed_entry>::iterator i = m_web_seeds.begin();
                i != m_web_seeds.end();)
            {
                std::list<web_seed_entry>::iterator w = i++;
                if (w->connection) continue;
                if (w->retry > time_now()) continue;
                if (w->resolving) continue;

                connect_to_url_seed(w);
            }
        }

        for (peer_iterator i = m_connections.begin();
            i != m_connections.end();)
        {
            peer_connection* p = *i;
            ++i;

            if (!p->ignore_stats())
                m_stat += p->statistics();

            // updates the peer connection's ul/dl bandwidth
            // resource requests
            TORRENT_TRY {
                p->second_tick(tick_interval_ms);
            }
            TORRENT_CATCH (std::exception& e)
            {
                TORRENT_DECLARE_DUMMY(std::exception, e);
                (void)e;
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_ERROR_LOGGING
                p->peer_log("*** ERROR %s", e.what());
#endif
                p->disconnect(errors::no_error, 1);
            }
        }
        if (m_ses.m_alerts.should_post<stats_alert>())
            m_ses.m_alerts.post_alert(stats_alert(get_handle(), tick_interval_ms, m_stat));

        accumulator += m_stat;
        m_total_uploaded += m_stat.last_payload_uploaded();
        m_total_downloaded += m_stat.last_payload_downloaded();
        m_stat.second_tick(tick_interval_ms);
    }

    void torrent::recalc_share_mode()
    {
        TORRENT_ASSERT(share_mode());
        if (is_seed()) return;

        int pieces_in_torrent = m_torrent_file->num_pieces();
        int num_seeds = 0;
        int num_peers = 0;
        int num_downloaders = 0;
        int missing_pieces = 0;
        int num_interested = 0;
        for (std::set<peer_connection*>::iterator i = m_connections.begin()
            , end(m_connections.end()); i != end; ++i)
        {
            peer_connection* p = *i;
            if (p->is_connecting()) continue;
            ++num_peers;
            if (p->is_seed())
            {
                ++num_seeds;
                continue;
            }

            if (p->share_mode()) continue;

            if ((*i)->is_peer_interested()) ++num_interested;
            ++num_downloaders;
            missing_pieces += pieces_in_torrent - p->num_have_pieces();
        }

        if (num_peers == 0) return;

        if (num_seeds * 100 / num_peers > 50
            && (num_peers * 100 / m_max_connections > 90
                || num_peers > 20))
        {
            // we are connected to more than 90% seeds (and we're beyond
            // 90% of the max number of connections). That will
            // limit our ability to upload. We need more downloaders.
            // disconnect some seeds so that we don't have more than 50%
            int to_disconnect = num_seeds - num_peers / 2;
            std::vector<peer_connection*> seeds;
            seeds.reserve(num_seeds);
            for (std::set<peer_connection*>::iterator i = m_connections.begin()
                , end(m_connections.end()); i != end; ++i)
            {
                peer_connection* p = *i;
                if (p->is_seed()) seeds.push_back(p);
            }

            std::random_shuffle(seeds.begin(), seeds.end());
            TORRENT_ASSERT(to_disconnect <= int(seeds.size()));
            for (int i = 0; i < to_disconnect; ++i)
                seeds[i]->disconnect(errors::upload_upload_connection);
        }

        if (num_downloaders == 0) return;

        // assume that the seeds are about as fast as us. During the time
        // we can download one piece, and upload one piece, each seed
        // can upload two pieces.
        missing_pieces -= 2 * num_seeds;

        if (missing_pieces <= 0) return;

        // missing_pieces represents our opportunity to download pieces
        // and share them more than once each

        // now, download at least one piece, otherwise download one more
        // piece if our downloaded (and downloading) pieces is less than 50%
        // of the uploaded bytes
        int num_downloaded_pieces = (std::max)(m_picker->num_have()
            , pieces_in_torrent - m_picker->num_filtered());

        if (num_downloaded_pieces * m_torrent_file->piece_length()
            * settings().share_mode_target > m_total_uploaded
            && num_downloaded_pieces > 0)
            return;

        // don't have more pieces downloading in parallel than 5% of the total
        // number of pieces we have downloaded
        if (int(m_picker->get_download_queue().size()) > num_downloaded_pieces / 20)
            return;

        // one more important property is that there are enough pieces
        // that more than one peer wants to download
        // make sure that there are enough downloaders for the rarest
        // piece. Go through all pieces, figure out which one is the rarest
        // and how many peers that has that piece

        std::vector<int> rarest_pieces;

        int num_pieces = m_torrent_file->num_pieces();
        int rarest_rarity = INT_MAX;
        bool prio_updated = false;
        for (int i = 0; i < num_pieces; ++i)
        {
            piece_picker::piece_pos const& pp = m_picker->piece_stats(i);
            if (pp.peer_count == 0) continue;
            if (pp.filtered() && (pp.have() || pp.downloading))
            {
                m_picker->set_piece_priority(i, 1);
                prio_updated = true;
                continue;
            }
            // don't count pieces we already have or are downloading
            if (!pp.filtered() || pp.have()) continue;
            if (int(pp.peer_count) > rarest_rarity) continue;
            if (int(pp.peer_count) == rarest_rarity)
            {
                rarest_pieces.push_back(i);
                continue;
            }

            rarest_pieces.clear();
            rarest_rarity = pp.peer_count;
            rarest_pieces.push_back(i);
        }

        if (prio_updated)
            m_policy.recalculate_connect_candidates();

        // now, rarest_pieces is a list of all pieces that are the rarest ones.
        // and rarest_rarity is the number of peers that have the rarest pieces

        // if there's only a single peer that doesn't have the rarest piece
        // it's impossible for us to download one piece and upload it
        // twice. i.e. we cannot get a positive share ratio
        if (num_peers - rarest_rarity < settings().share_mode_target) return;

        // we might be able to do better than a share ratio of 2 if there are
        // enough downloaders of the pieces we already have.
        // TODO: go through the pieces we have and count the total number
        // of downloaders we have. Only count peers that are interested in us
        // since some peers might not send have messages for pieces we have
        // it num_interested == 0, we need to pick a new piece

        // now, pick one of the rarest pieces to download
        int pick = random() % rarest_pieces.size();
        bool was_finished = is_finished();
        m_picker->set_piece_priority(rarest_pieces[pick], 1);
        update_peer_interest(was_finished);

        m_policy.recalculate_connect_candidates();
    }

    void torrent::refresh_explicit_cache(int cache_size)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (!ready_for_connections()) return;
        // rotate the cached pieces

        // add blocks_per_piece / 2 in order to round to closest whole piece
        int blocks_per_piece = m_torrent_file->piece_length() / block_size();
        int num_cache_pieces = (cache_size + blocks_per_piece / 2) / blocks_per_piece;
        if (num_cache_pieces > m_torrent_file->num_pieces())
            num_cache_pieces = m_torrent_file->num_pieces();

        std::vector<int> avail_vec;
        if (has_picker())
        {
            m_picker->get_availability(avail_vec);
        }
        else
        {
            // we don't keep track of availability, do it the expensive way
            // do a linear search from the first piece
            for (int i = 0; i < m_torrent_file->num_pieces(); ++i)
            {
                int availability = 0;
                if (!have_piece(i))
                {
                    avail_vec.push_back(INT_MAX);
                    continue;
                }

                for (const_peer_iterator j = this->begin(); j != this->end(); ++j)
                    if ((*j)->has_piece(i)) ++availability;
                avail_vec.push_back(availability);
            }
        }

        // now pick the num_cache_pieces rarest pieces from avail_vec
        std::vector<std::pair<int, int> > pieces(m_torrent_file->num_pieces());
        for (int i = 0; i < m_torrent_file->num_pieces(); ++i)
        {
            pieces[i].second = i;
            if (!have_piece(i)) pieces[i].first = INT_MAX;
            else pieces[i].first = avail_vec[i];
        }

        // decrease the availability of the pieces that are
        // already in the read cache, to move them closer to
        // the beginning of the pieces list, and more likely
        // to be included in this round of cache pieces
        std::vector<cached_piece_info> ret;
        m_ses.m_disk_thread.get_cache_info(info_hash(), ret);
        // remove write cache entries
        ret.erase(std::remove_if(ret.begin(), ret.end()
            , boost::bind(&cached_piece_info::kind, _1) == cached_piece_info::write_cache)
            , ret.end());
        for (std::vector<cached_piece_info>::iterator i = ret.begin()
            , end(ret.end()); i != end; ++i)
        {
            --pieces[i->piece].first;
        }

        std::random_shuffle(pieces.begin(), pieces.end());
        std::stable_sort(pieces.begin(), pieces.end()
            , boost::bind(&std::pair<int, int>::first, _1) <
            boost::bind(&std::pair<int, int>::first, _2));
        avail_vec.clear();
        for (int i = 0; i < num_cache_pieces; ++i)
        {
            if (pieces[i].first == INT_MAX) break;
            avail_vec.push_back(pieces[i].second);
        }

        if (!avail_vec.empty())
        {
            // the number of pieces to cache for this torrent is proportional
            // the number of peers it has, divided by the total number of peers.
            // Each peer gets an equal share of the cache

            avail_vec.resize((std::min)(num_cache_pieces, int(avail_vec.size())));

            for (std::vector<int>::iterator i = avail_vec.begin()
                , end(avail_vec.end()); i != end; ++i)
                filesystem().async_cache(*i, boost::bind(&torrent::on_disk_cache_complete
                    , shared_from_this(), _1, _2));
        }
    }

    void torrent::get_suggested_pieces(std::vector<int>& s) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        if (settings().suggest_mode == session_settings::no_piece_suggestions)
        {
            s.clear();
            return;
        }

        std::vector<cached_piece_info> ret;
        m_ses.m_disk_thread.get_cache_info(info_hash(), ret);
        ptime now = time_now();

        // remove write cache entries
        ret.erase(std::remove_if(ret.begin(), ret.end()
            , boost::bind(&cached_piece_info::kind, _1) == cached_piece_info::write_cache)
            , ret.end());

        // sort by how new the cached entry is, new pieces first
        std::sort(ret.begin(), ret.end()
            , boost::bind(&cached_piece_info::last_use, _1)
            < boost::bind(&cached_piece_info::last_use, _2));

        // cut off the oldest pieces that we don't want to suggest
        // if we have an explicit cache, it's much more likely to
        // stick around, so we should suggest all pieces
        int num_pieces_to_suggest = int(ret.size());
        if (num_pieces_to_suggest == 0) return;

        if (!settings().explicit_read_cache)
            num_pieces_to_suggest = (std::max)(1, int(ret.size() / 2));
        ret.resize(num_pieces_to_suggest);

        std::transform(ret.begin(), ret.end(), std::back_inserter(s)
            , boost::bind(&cached_piece_info::piece, _1));
    }

    void torrent::add_stats(stat const& s)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        // these stats are propagated to the session
        // stats the next time second_tick is called
        m_stat += s;
    }

    void torrent::request_time_critical_pieces()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        // build a list of peers and sort it by download_queue_time
        // we use this sorted list to determine which peer we should
        // request a block from. The higher up a peer is in the list,
        // the sooner we will fully download the block we request.
        std::vector<peer_connection*> peers;
        peers.reserve(m_connections.size());
        std::remove_copy_if(m_connections.begin(), m_connections.end()
            , std::back_inserter(peers), !boost::bind(&peer_connection::can_request_time_critical, _1));
        std::sort(peers.begin(), peers.end()
            , boost::bind(&peer_connection::download_queue_time, _1, 16*1024)
            < boost::bind(&peer_connection::download_queue_time, _2, 16*1024));

        std::set<peer_connection*> peers_with_requests;

        std::vector<piece_block> interesting_blocks;
        std::vector<piece_block> backup1;
        std::vector<piece_block> backup2;
        std::vector<int> ignore;

        ptime now = time_now();

        // now, iterate over all time critical pieces, in order of importance, and
        // request them from the peers, in order of responsiveness. i.e. request
        // the most time critical pieces from the fastest peers.
        for (std::list<time_critical_piece>::iterator i = m_time_critical_pieces.begin()
            , end(m_time_critical_pieces.end()); i != end; ++i)
        {
            if (peers.empty()) break;

            if (i != m_time_critical_pieces.begin() && i->deadline > now
                + milliseconds(m_average_piece_time + m_piece_time_deviation * 4))
            {
                // don't request pieces whose deadline is too far in the future
                // this is one of the termination conditions. We don't want to
                // send requests for all pieces in the torrent right away
                break;
            }

            // loop until every block has been requested from this piece (i->piece)
            do
            {
                // pick the peer with the lowest download_queue_time that has i->piece
                std::vector<peer_connection*>::iterator p = std::find_if(peers.begin(), peers.end()
                    , boost::bind(&peer_connection::has_piece, _1, i->piece));

                // obviously we'll have to skip it if we don't have a peer that has this piece
                if (p == peers.end()) break;
                peer_connection& c = **p;

                interesting_blocks.clear();
                backup1.clear();
                backup2.clear();
                // specifically request blocks with no affinity towards fast or slow
                // pieces. If we would, the picked block might end up in one of
                // the backup lists
                m_picker->add_blocks(i->piece, c.get_bitfield(), interesting_blocks
                    , backup1, backup2, 1, 0, c.peer_info_struct()
                    , ignore, piece_picker::none, 0);

                std::vector<pending_block> const& rq = c.request_queue();

                bool added_request = false;

                if (!interesting_blocks.empty() && std::find_if(rq.begin(), rq.end()
                    , has_block(interesting_blocks.front())) != rq.end())
                {
                    c.make_time_critical(interesting_blocks.front());
                    added_request = true;
                }
                else if (!interesting_blocks.empty())
                {
                    if (!c.add_request(interesting_blocks.front(), peer_connection::req_time_critical))
                    {
                        peers.erase(p);
                        continue;
                    }
                    added_request = true;
                }

                // TODO: if there's been long enough since we requested something
                // from this piece, request one of the backup blocks (the one with
                // the least number of requests to it) and update the last request
                // timestamp

                if (added_request)
                {
                    peers_with_requests.insert(peers_with_requests.begin(), &c);
                    if (i->first_requested == min_time()) i->first_requested = now;

                    if (!c.can_request_time_critical())
                    {
                        peers.erase(p);
                    }
                    else
                    {
                        // resort p, since it will have a higher download_queue_time now
                        while (p != peers.end()-1 && (*p)->download_queue_time() > (*(p+1))->download_queue_time())
                        {
                            std::iter_swap(p, p+1);
                            ++p;
                        }
                    }
                }

            } while (!interesting_blocks.empty());
        }

        // commit all the time critical requests
        for (std::set<peer_connection*>::iterator i = peers_with_requests.begin()
            , end(peers_with_requests.end()); i != end; ++i)
        {
            (*i)->send_block_requests();
        }
    }

    std::set<std::string> torrent::web_seeds(web_seed_entry::type_t type) const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        std::set<std::string> ret;
        for (std::list<web_seed_entry>::const_iterator i = m_web_seeds.begin()
            , end(m_web_seeds.end()); i != end; ++i)
        {
            if (i->type != type) continue;
            ret.insert(i->url);
        }
        return ret;
    }

    void torrent::retry_web_seed(peer_connection* p, int retry)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        std::list<web_seed_entry>::iterator i = std::find_if(m_web_seeds.begin(), m_web_seeds.end()
            , (boost::bind(&web_seed_entry::connection, _1) == p));

        TORRENT_ASSERT(i != m_web_seeds.end());
        if (i == m_web_seeds.end()) return;
        if (retry == 0) retry = m_ses.settings().urlseed_wait_retry;
        i->retry = time_now() + seconds(retry);
    }

    bool torrent::try_connect_peer()
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(want_more_peers());
        if (m_deficit_counter < 100) return false;
        m_deficit_counter -= 100;
        bool ret = m_policy.connect_one_peer(m_ses.session_time());
        return ret;
    }

    void torrent::give_connect_points(int points)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(points <= 100);
        TORRENT_ASSERT(points > 0);
        TORRENT_ASSERT(want_more_peers());
        m_deficit_counter += points;
    }

    void torrent::add_peer(tcp::endpoint const& adr, int source)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        peer_id id(0);
        m_policy.add_peer(adr, id, source, 0);
    }

    void torrent::async_verify_piece(int piece_index, boost::function<void(int)> const& f)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
//		INVARIANT_CHECK;

        TORRENT_ASSERT(m_storage);
        TORRENT_ASSERT(m_storage->refcount() > 0);
        TORRENT_ASSERT(piece_index >= 0);
        TORRENT_ASSERT(piece_index < m_torrent_file->num_pieces());
        TORRENT_ASSERT(piece_index < (int)m_picker->num_pieces());
        TORRENT_ASSERT(!m_picker || !m_picker->have_piece(piece_index));
#ifdef TORRENT_DEBUG
        if (m_picker)
        {
            int blocks_in_piece = m_picker->blocks_in_piece(piece_index);
            for (int i = 0; i < blocks_in_piece; ++i)
            {
                TORRENT_ASSERT(m_picker->num_peers(piece_block(piece_index, i)) == 0);
            }
        }
#endif

        m_storage->async_hash(piece_index, boost::bind(&torrent::on_piece_verified
            , shared_from_this(), _1, _2, f));
#if defined TORRENT_DEBUG && !defined TORRENT_DISABLE_INVARIANT_CHECKS
        check_invariant();
#endif
    }

    void torrent::on_piece_verified(int ret, disk_io_job const& j
        , boost::function<void(int)> f)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        // return value:
        // 0: success, piece passed hash check
        // -1: disk failure
        // -2: hash check failed

        if (ret == -1) handle_disk_error(j);
        f(ret);
    }

    tcp::endpoint torrent::current_tracker() const
    {
        return m_tracker_address;
    }

    announce_entry* torrent::find_tracker(tracker_request const& r)
    {
        std::vector<announce_entry>::iterator i = std::find_if(
            m_trackers.begin(), m_trackers.end()
            , boost::bind(&announce_entry::url, _1) == r.url);
        if (i == m_trackers.end()) return 0;
        return &*i;
    }

#if !TORRENT_NO_FPU
    void torrent::file_progress(std::vector<float>& fp) const
    {
        fp.clear();
        fp.resize(m_torrent_file->num_files(), 1.f);
        if (is_seed()) return;

        std::vector<size_type> progress;
        file_progress(progress);
        for (int i = 0; i < m_torrent_file->num_files(); ++i)
        {
            file_entry const& f = m_torrent_file->file_at(i);
            if (f.size == 0) fp[i] = 1.f;
            else fp[i] = float(progress[i]) / f.size;
        }
    }
#endif

    void torrent::file_progress(std::vector<size_type>& fp, int flags) const
    {
        TORRENT_ASSERT(valid_metadata());

        fp.resize(m_torrent_file->num_files(), 0);

        if (flags & torrent_handle::piece_granularity)
        {
            std::copy(m_file_progress.begin(), m_file_progress.end(), fp.begin());
            return;
        }

        if (is_seed())
        {
            for (int i = 0; i < m_torrent_file->num_files(); ++i)
                fp[i] = m_torrent_file->files().at(i).size;
            return;
        }

        TORRENT_ASSERT(has_picker());

        for (int i = 0; i < m_torrent_file->num_files(); ++i)
        {
            peer_request ret = m_torrent_file->files().map_file(i, 0, 0);
            size_type size = m_torrent_file->files().at(i).size;

// zero sized files are considered
// 100% done all the time
            if (size == 0)
            {
                fp[i] = 0;
                continue;
            }

            size_type done = 0;
            while (size > 0)
            {
                size_type bytes_step = (std::min)(size_type(m_torrent_file->piece_size(ret.piece)
                    - ret.start), size);
                if (m_picker->have_piece(ret.piece)) done += bytes_step;
                ++ret.piece;
                ret.start = 0;
                size -= bytes_step;
            }
            TORRENT_ASSERT(size == 0);

            fp[i] = done;
        }

        const std::vector<piece_picker::downloading_piece>& q
            = m_picker->get_download_queue();

        for (std::vector<piece_picker::downloading_piece>::const_iterator
            i = q.begin(), end(q.end()); i != end; ++i)
        {
            size_type offset = size_type(i->index) * m_torrent_file->piece_length();
            torrent_info::file_iterator file = m_torrent_file->file_at_offset(offset);
            int file_index = file - m_torrent_file->begin_files();
            int num_blocks = m_picker->blocks_in_piece(i->index);
            piece_picker::block_info const* info = i->info;
            for (int k = 0; k < num_blocks; ++k)
            {
                TORRENT_ASSERT(file != m_torrent_file->end_files());
                TORRENT_ASSERT(offset == size_type(i->index) * m_torrent_file->piece_length()
                    + k * block_size());
                TORRENT_ASSERT(offset < m_torrent_file->total_size());
                while (offset >= file->offset + file->size)
                {
                    ++file;
                    ++file_index;
                }
                TORRENT_ASSERT(file != m_torrent_file->end_files());

                size_type block = block_size();

                if (info[k].state == piece_picker::block_info::state_none)
                {
                    offset += block;
                    continue;
                }

                if (info[k].state == piece_picker::block_info::state_requested)
                {
                    block = 0;
                    policy::peer* p = static_cast<policy::peer*>(info[k].peer);
                    if (p && p->connection)
                    {
                        boost::optional<piece_block_progress> pbp
                            = p->connection->downloading_piece_progress();
                        if (pbp && pbp->piece_index == i->index && pbp->block_index == k)
                            block = pbp->bytes_downloaded;
                        TORRENT_ASSERT(block <= block_size());
                    }

                    if (block == 0)
                    {
                        offset += block_size();
                        continue;
                    }
                }

                if (offset + block > file->offset + file->size)
                {
                    int left_over = int(block_size() - block);
                    // split the block on multiple files
                    while (block > 0)
                    {
                        TORRENT_ASSERT(offset <= file->offset + file->size);
                        size_type slice = (std::min)(file->offset + file->size - offset
                            , block);
                        fp[file_index] += slice;
                        offset += slice;
                        block -= slice;
                        TORRENT_ASSERT(offset <= file->offset + file->size);
                        if (offset == file->offset + file->size)
                        {
                            ++file;
                            ++file_index;
                            if (file == m_torrent_file->end_files())
                            {
                                offset += block;
                                break;
                            }
                        }
                    }
                    offset += left_over;
                    TORRENT_ASSERT(offset == size_type(i->index) * m_torrent_file->piece_length()
                        + (k+1) * block_size());
                }
                else
                {
                    fp[file_index] += block;
                    offset += block_size();
                }
                TORRENT_ASSERT(file_index <= m_torrent_file->num_files());
            }
        }
    }

    void torrent::set_state(torrent_status::state_t s)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
#ifdef TORRENT_DEBUG
        if (s != torrent_status::checking_files
            && s != torrent_status::queued_for_checking)
        {
            // the only valid transition away from queued_for_checking
            // is to checking_files. One exception is to finished
            // in case all the files are marked with priority 0
            if (m_queued_for_checking)
            {
                std::vector<int> pieces;
                m_picker->piece_priorities(pieces);
                // make sure all pieces have priority 0
                TORRENT_ASSERT(std::accumulate(pieces.begin(), pieces.end(), 0) == 0);
            }
        }
        if (s == torrent_status::seeding)
            TORRENT_ASSERT(is_seed());
        if (s == torrent_status::finished)
            TORRENT_ASSERT(is_finished());
        if (s == torrent_status::downloading && m_state == torrent_status::finished)
            TORRENT_ASSERT(!is_finished());
#endif

        if (int(m_state) == s) return;
        if (m_ses.m_alerts.should_post<state_changed_alert>())
            m_ses.m_alerts.post_alert(state_changed_alert(get_handle(), s, (torrent_status::state_t)m_state));
        m_state = s;

#ifndef TORRENT_DISABLE_EXTENSIONS
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                (*i)->on_state(m_state);
            } TORRENT_CATCH (std::exception&) {}
        }
#endif
    }

#ifndef TORRENT_DISABLE_EXTENSIONS
    void torrent::notify_extension_add_peer(tcp::endpoint const& ip
        , int src, int flags)
    {
        for (extension_list_t::iterator i = m_extensions.begin()
            , end(m_extensions.end()); i != end; ++i)
        {
            TORRENT_TRY {
                (*i)->on_add_peer(ip, src, flags);
            } TORRENT_CATCH (std::exception&) {}
        }
    }
#endif

    void torrent::status(torrent_status* st, boost::uint32_t flags)
    {
        INVARIANT_CHECK;

        ptime now = time_now();

        st->handle = get_handle();
        st->info_hash = info_hash();

        st->listen_port = 0;
#ifdef TORRENT_USE_OPENSSL
        if (is_ssl_torrent() && m_ssl_acceptor) st->listen_port = m_ssl_acceptor->external_port;
#endif

        st->has_incoming = m_has_incoming;
        if (m_error) st->error = m_error.message() + ": " + m_error_file;
        st->seed_mode = m_seed_mode;

        st->added_time = m_added_time;
        st->completed_time = m_completed_time;

        st->last_scrape = m_last_scrape;
        st->share_mode = m_share_mode;
        st->upload_mode = m_upload_mode;
        st->up_bandwidth_queue = 0;
        st->down_bandwidth_queue = 0;
        st->priority = m_priority;

        st->num_peers = (int)std::count_if(m_connections.begin(), m_connections.end()
            , !boost::bind(&peer_connection::is_connecting, _1));

        st->list_peers = m_policy.num_peers();
        st->list_seeds = m_policy.num_seeds();
        st->connect_candidates = m_policy.num_connect_candidates();
        st->seed_rank = seed_rank(settings());

        st->all_time_upload = m_total_uploaded;
        st->all_time_download = m_total_downloaded;

        // activity time
        st->active_time = m_active_time;
        st->active_time = m_active_time;
        st->seeding_time = m_seeding_time;
        st->time_since_upload = m_last_upload;
        st->time_since_download = m_last_download;

        st->storage_mode = (storage_mode_t)m_storage_mode;

        st->num_complete = (m_complete == 0xffffff) ? -1 : m_complete;
        st->num_incomplete = (m_incomplete == 0xffffff) ? -1 : m_incomplete;
        st->paused = is_torrent_paused();
        st->auto_managed = m_auto_managed;
        st->sequential_download = m_sequential_download;
        st->is_seeding = is_seed();
        st->is_finished = is_finished();
        st->has_metadata = valid_metadata();
        bytes_done(*st, flags & torrent_handle::query_accurate_download_counters);
        TORRENT_ASSERT(st->total_wanted_done >= 0);
        TORRENT_ASSERT(st->total_done >= st->total_wanted_done);

        // payload transfer
        st->total_payload_download = m_stat.total_payload_download();
        st->total_payload_upload = m_stat.total_payload_upload();

        // total transfer
        st->total_download = m_stat.total_payload_download()
            + m_stat.total_protocol_download();
        st->total_upload = m_stat.total_payload_upload()
            + m_stat.total_protocol_upload();

        // failed bytes
        st->total_failed_bytes = m_total_failed_bytes;
        st->total_redundant_bytes = m_total_redundant_bytes;

        // transfer rate
        st->download_rate = m_stat.download_rate();
        st->upload_rate = m_stat.upload_rate();
        st->download_payload_rate = m_stat.download_payload_rate();
        st->upload_payload_rate = m_stat.upload_payload_rate();

        if (m_waiting_tracker && !is_paused())
            st->next_announce = boost::posix_time::seconds(
                total_seconds(next_announce() - now));
        else
            st->next_announce = boost::posix_time::seconds(0);

        if (st->next_announce.is_negative())
            st->next_announce = boost::posix_time::seconds(0);

        st->announce_interval = boost::posix_time::seconds(0);

        st->current_tracker.clear();
        if (m_last_working_tracker >= 0)
        {
            TORRENT_ASSERT(m_last_working_tracker < int(m_trackers.size()));
            st->current_tracker = m_trackers[m_last_working_tracker].url;
        }
        else
        {
            std::vector<announce_entry>::const_iterator i;
            for (i = m_trackers.begin(); i != m_trackers.end(); ++i)
            {
                if (!i->updating) continue;
                st->current_tracker = i->url;
                break;
            }
        }

        if ((flags & torrent_handle::query_verified_pieces))
        {
            st->verified_pieces = m_verified;
        }

        st->num_uploads = m_num_uploads;
        st->uploads_limit = m_max_uploads;
        st->num_connections = int(m_connections.size());
        st->connections_limit = m_max_connections;
        // if we don't have any metadata, stop here

        st->queue_position = queue_position();
        st->need_save_resume = need_save_resume_data();
        st->ip_filter_applies = m_apply_ip_filter;

        st->state = (torrent_status::state_t)m_state;

        if (!valid_metadata())
        {
            st->state = torrent_status::downloading_metadata;
            st->progress_ppm = m_progress_ppm;
#if !TORRENT_NO_FPU
            st->progress = m_progress_ppm / 1000000.f;
#endif
            st->block_size = 0;
            return;
        }

        st->block_size = block_size();

        if (m_state == torrent_status::checking_files)
        {
            st->progress_ppm = m_progress_ppm;
#if !TORRENT_NO_FPU
            st->progress = m_progress_ppm / 1000000.f;
#endif
        }
        else if (st->total_wanted == 0)
        {
            st->progress_ppm = 1000000;
            st->progress = 1.f;
        }
        else
        {
            st->progress_ppm = st->total_wanted_done * 1000000
                / st->total_wanted;
#if !TORRENT_NO_FPU
            st->progress = st->progress_ppm / 1000000.f;
#endif
        }

        if (has_picker())
        {
            st->sparse_regions = m_picker->sparse_regions();
            int num_pieces = m_picker->num_pieces();
            st->pieces.resize(num_pieces, false);
            for (int i = 0; i < num_pieces; ++i)
                if (m_picker->have_piece(i)) st->pieces.set_bit(i);
        }
        else if (is_seed())
        {
            int num_pieces = m_torrent_file->num_pieces();
            st->pieces.resize(num_pieces, true);
        }
        st->num_pieces = num_have();
        st->num_seeds = num_seeds();
        if ((flags & torrent_handle::query_distributed_copies) && m_picker.get())
        {
            boost::tie(st->distributed_full_copies, st->distributed_fraction) =
                m_picker->distributed_copies();
#if TORRENT_NO_FPU
            st->distributed_copies = -1.f;
#else
            st->distributed_copies = st->distributed_full_copies
                + float(st->distributed_fraction) / 1000;
#endif
        }
        else
        {
            st->distributed_full_copies = -1;
            st->distributed_fraction = -1;
            st->distributed_copies = -1.f;
        }

        if (flags & torrent_handle::query_last_seen_complete)
        {
            time_t last = last_seen_complete();
            for (std::set<peer_connection*>::const_iterator i = m_connections.begin()
                , end(m_connections.end()); i != end; ++i)
            {
                last = (std::max)(last, (*i)->last_seen_complete());
            }
            st->last_seen_complete = last;
        }
        else
        {
            st->last_seen_complete = 0;
        }
    }

    void torrent::add_redundant_bytes(int b)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(b > 0);
        m_total_redundant_bytes += b;
        m_ses.add_redundant_bytes(b);
//		TORRENT_ASSERT(m_total_redundant_bytes + m_total_failed_bytes
//			<= m_stat.total_payload_download());
    }

    void torrent::add_failed_bytes(int b)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        TORRENT_ASSERT(b > 0);
        m_total_failed_bytes += b;
        m_ses.add_failed_bytes(b);
//		TORRENT_ASSERT(m_total_redundant_bytes + m_total_failed_bytes
//			<= m_stat.total_payload_download());
    }

    int torrent::num_seeds() const
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        INVARIANT_CHECK;

        int ret = 0;
        for (std::set<peer_connection*>::const_iterator i = m_connections.begin()
            , end(m_connections.end()); i != end; ++i)
            if ((*i)->is_seed()) ++ret;
        return ret;
    }

    // TODO: with some response codes, we should just consider
    // the tracker as a failure and not retry
    // it anymore
    void torrent::tracker_request_error(tracker_request const& r
        , int response_code, error_code const& ec, const std::string& msg
        , int retry_interval)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());

        INVARIANT_CHECK;

#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
        debug_log("*** tracker error: " + ec.message() + " " + msg);
#endif
        if (r.kind == tracker_request::announce_request)
        {
            announce_entry* ae = find_tracker(r);
            if (ae)
            {
                ae->failed(retry_interval);
                ae->last_error = ec;
                ae->message = msg;
                int tracker_index = ae - &m_trackers[0];
#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
                debug_log("*** increment tracker fail count ["
                    + std::string(to_string(ae->fails).elems) + "]");
#endif
                deprioritize_tracker(tracker_index);
            }
            if (m_ses.m_alerts.should_post<tracker_error_alert>())
            {
                m_ses.m_alerts.post_alert(tracker_error_alert(get_handle()
                    , ae?ae->fails:0, response_code, r.url, ec, msg));
            }
        }
        else if (r.kind == tracker_request::scrape_request)
        {
            if (m_ses.m_alerts.should_post<scrape_failed_alert>())
            {
                m_ses.m_alerts.post_alert(scrape_failed_alert(get_handle(), r.url, ec));
            }
        }
        // announce to the next working tracker
        if ((!m_abort && !is_paused()) || r.event == tracker_request::stopped)
            announce_with_tracker(r.event);
        update_tracker_timer(time_now());
    }


#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING || defined TORRENT_ERROR_LOGGING
    void torrent::debug_log(const std::string& line)
    {
        TORRENT_ASSERT(m_ses.is_network_thread());
        (*m_ses.m_logger) << time_now_string() << " " << line << "\n";
    }
#endif

}

